Tracking motions of single electrons at the space-time limit with attosecond time resolution or the extension of the Heisenberg Uncertainty Principle

Amazing stuff! Very impressive! This could be a breakthrough!

"... developed subfemtosecond scanning tunneling microscopy to directly visualize the quantum motion of individual electrons at this space-time limit as they tunneled through an energy barrier.

Modulating the barrier with the carrier field of near-infrared waveforms produced isolated sub–1-femtosecond electronic wave packets, the spatial extent of which depended on a complex interplay between multiphoton and field-driven dynamics. By balancing quantum path interference, the authors minimized the wave function’s space-time volume down to the attosecond-angstrom scale."

"... Between position and time, however, there is no Heisenberg uncertainty principle. A research team ... has now observed for the first time that the location and time evolution of an electron cannot be measured with arbitrary precision simultaneously. This so-called space-time limit has important implications for future applications. ...

ultrafast microscopes are developed and used to directly capture the motion of electrons, atoms, and molecules in microscopic slow-motion movies with the highest possible spatial and temporal resolution.

Ten years ago ... the motion of a single molecule in space and time was resolved for the first time using ultrafast scanning tunneling microscopy.

Compared to atoms and molecules, on this length scale electrons move a thousand times faster—namely, on time scales of attoseconds. ...

To achieve a corresponding increase in temporal resolution compared to previous experiments and to directly image and control the quantum dynamics of individual electrons, the researchers developed a new laser system.

Using its laser pulses they control electron motion on these extreme time scales in such a way that the electrons transfer from an atomically sharp metal tip to a silver surface over a distance of only a few atomic diameters. These electron movements are measured as current, and the temporal information is obtained by using two pulses of light. ...

The electron motion observed in this way exhibits signatures on attosecond timescales—which means that the light pulses can transfer electrons on these timescales, and one can watch them do so.

What makes this special is that the electrons do not move like classical particles. Rather, as quantum mechanical waves, the electrons penetrate the energy barrier between the tip and the sample, for which they actually do not possess enough energy according to the laws of classical physics. They “tunnel” through it, as if they were passing through a massive wall without destroying it. ...

To gain a better understanding of microscopic electron dynamics at the “space-time limit,” ... conducted complex quantum simulations. The calculations explain the experimental results with remarkable accuracy. They also show that the electron does not follow the light field immediately, but with a tiny delay of 500 attoseconds. ...

In this frontier region of the smallest spatial and temporal scales, the fundamental physical limits of quantum physics become apparent on multiple levels. The effect of the laser pulses, for example, cannot be clearly assigned to either the wave or photon picture of light, but bears features of both—and this is precisely what enabled the researchers to penetrate so deeply into the “space-time limit.” When electrons are moved by light pulses on such short time scales, this has complex consequences for the spatial distribution of the electrons, which are described in quantum mechanics as wave packets.

 “The more precisely we want to pin down the electron’s position in time, the more energy we need to provide. And as a result, the electron wave packet spreads out more spatially.” The team investigated this relationship using a single atom placed on the surface to confine the electron wave packets atomically just before the light pulses arrive. This allowed them to directly determine the relationship between the spatial and temporal spread of the electron wave packets. Fortunately, despite strong excitation, the electron wave packets remain spatially defined with sufficient sharpness to enable atomically resolved microscopy on attosecond timescales.

With this latest breakthrough, the team is pushing the boundaries of a previously only vaguely suspected spatiotemporal limit of quantum mechanical electron wave functions, in order to systematically investigate for the first time how the temporal dynamics of electrons shape the spatial structure of their wave function. This also opens up entirely new possibilities for applications. For example, transferring an electron to a molecule corresponds to the smallest possible charge transfer; however, if the electron is confined to a tiny space-time volume, this corresponds to extremely high local peak current densities of up to 1 trillion amperes per square centimeter."

From the abstract:

"The dynamics of an electronic wavefunction often have non-trivial consequences on its spatial distribution, for example, during tunnelling or chemical bond formation.

Yet, revealing spatio-temporal coupling requires ultrafast videography at the intrinsic size of electronic wavefunctions, at the so-called space-time limit.

Here we experimentally access the intrinsic quantum motion of individual electrons at the space-time limit while they are tunnelling through an energy barrier, using atomic-scale lightwave-driven scanning tunnelling microscopy with attosecond time resolution. 

While modulating the tunnelling barrier with two time-delayed near-infrared pulses forming phase-controlled single-cycle waveforms, isolated electron tunnelling transients shorter than 1 fs are identified.

The measured spatial extension depends on the interplay of multi-photon and field-driven dynamics, as confirmed by full quantum simulations.

We experimentally localize the attosecond-confined tunnelling wave packet on the angstrom scale and use it to map a single copper adatom on a silver surface. This fusion of attosecond science with atomic-scale scanning tunnelling microscopy makes it possible to study wavefunction dynamics inside atoms, molecules and solids."

In Other Journals | Science

Microscopy at the Space-Time Limit (original news release) "Ultrafast scanning tunneling microscopy at the Regensburg Center for Ultrafast Nanoscopy (RUN) reaches the quantum mechanical space-time limit for the first time"

Tracking electrons at the space-time limit (open access)

Fig. 1: Attosecond lightwave STM [scanning tunneling microscopy].

Fig. 2: Evolution of lightwave-driven tunnelling currents with [tau] delay time 

Fig. 4: Atomically resolved subcycle currents.

Quantum computer microscope is set to significantly improve electron microscopy using few single electrons

"... A team ... has now developed a way to make use of the quantum information carried by electrons in an electron microscope: The electron beam is coupled to a quantum computer, opening up entirely new possibilities for working with the quantum information of the electrons.

This is particularly important for sensitive samples that cannot be bombarded with arbitrarily large numbers of electrons. ..."

"... “Today, we can image tiny details on the atomic scale,” ... “However, this requires a large number of electrons. And not every sample can be exposed to so many electrons without being damaged. This is often a problem, particularly when imaging biological samples such as individual proteins.” ...

If, however, more information can be extracted from each individual electron than before, a smaller number of electrons is sufficient. The team has now found a method to achieve precisely this ..."

From the abstract:

"Freely propagating electrons may serve as quantum probes that can become coherently correlated with other quantum systems, offering access to advanced metrological resources.

We propose a setup that coherently couples free electrons in an electron microscope to a trapped-ion quantum processor, enabling non-destructive, quantum-coherent detection and the accumulation of information across multiple electrons. Our analysis shows that single electrons can induce resolvable qubit excitations, establishing a platform for practical applications such as quantum-enhanced, dose-efficient electron microscopy."

Quantum computer microscope is set to significantly improve electron microscopy

The Quantum Computer Microscope (original news release) "A new invention is set to significantly improve electron microscopy: a small quantum computer is integrated directly into the microscope."

Coupling free electrons to a trapped-ion quantum computer (preprint, open access)

Researchers break diffraction barrier in super-resolution microscopy

Good news! This could be a breakthrough!

"... have developed a groundbreaking super-resolution imaging technology that allows scientists to visualize molecular structures with sub-angstrom-level localization precision — three orders of magnitude beyond the nanometer limits of standard fluorescent dyes — while drastically simplifying the imaging process.

Unlike traditional dyes that fade rapidly under illumination and limit data collection, the platform, called U-STORM (Upconversion enabled Stochastic Optical Reconstruction Microscopy) utilizes a new class of compositionally engineered upconverting nanoparticles (UCNPs) that blink spontaneously and indefinitely. ..."

From the abstract:

"Single-molecule localization microscopy enables high-resolution biological imaging, but its precision is limited by the rapid photobleaching of conventional fluorophores.

Multicolour imaging is further constrained by the need for spectrally distinct dyes requiring separate excitations or sequential acquisition.

Here we show that small (~10 nm) upconverting nanoparticles can be compositionally tuned to exhibit spontaneous, sustained blinking under single near-infrared excitation without optical or chemical modulation.

By adjusting sensitizer (Yb3+)–emitter (Tm3+/Er3+) ratios, we identify a regime with intrinsic ON–OFF switching and low duty cycles (~0.9%) without photobleaching or statistical aging, enabling repeated localizations and sub-ångström precision (0.62 Å over 88,000 localizations) in upconversion-enabled stochastic optical reconstruction microscopy.

By elucidating the underlying physical mechanism of this blinking, we engineered blue- and red-emitting probes for multicolour upconversion-enabled stochastic optical reconstruction microscopy.

This technique enables the resolution of tightly packed UCNPs and the visualization of epidermal growth factor receptor dimers and multimers on cell membranes at single-protein resolution, all achieved with a simple optical setup without imaging buffers."

MIT and Broad Institute researchers break diffraction barrier in super-resolution microscopy | MIT News | Massachusetts Institute of Technology "New U-STORM imaging technology lets scientists view molecular structures in subatomic detail — about 1,000 times clearer than traditional dyes — while making the microscope process much simpler."

Spontaneous and indefinite blinking in upconverting nanoparticles for ångström-precision multicolour super-resolution imaging (open access)

Fig. 1: U-STORM workflow and route to ångström-level precision.

Fig. 3: Super-resolution imaging with high precision and accuracy using blue-emitting U-STORM probe.

Thousandfold Expansion Microscopy

Amazing stuff!

"... In a preprint posted last month to bioRxiv, Boyden and colleagues describe “thousandfold expansion microscopy” or 1000ExM, a method that expands tissues as much as 1000x in every direction—a one billion times increase in volume.

First, they improved upon the expanding gel used to spread things apart. They also figured out how to bind target molecules to this gel, allowing them to break apart proteins and other bonded entities while keeping their pieces relative in space. Lastly, they tinkered with their technique to allow them to repeat the expansion step over and over again. ..."

From the abstract:

"Biological macromolecules, such as proteins, are made of concatenated building blocks. We hypothesized that individual protein residues could be imaged by anchoring their side chains to a swellable polymer, cleaving backbone amide bonds, and expanding residues away from each other to a degree that enables them to be visualized separately.

We introduce thousandfold expansion microscopy (1000ExM), a four-network interpenetrating hydrogel architecture that enables successive expansion from ∼18-fold to >1000-fold (one billion-fold in volume). Protein and peptide structures are maintained across these expansion factors, as verified by analyses of proteins with known structures (nanobodies, GFP) and a well-studied peptide (mCLING). Computational analysis indicates that 1000ExM resolves adjacent amino acid residues, thereby achieving sub-nanometer precision on conventional light microscopes. We anticipate that 1000ExM will find wide utility in protein visualization and identification, potentially even in intact cells and tissues."

ScienceAdviser

Thousandfold Expansion Microscopy (preprint, open access)

A small peptide with one end tagged in purple and certain amino acids in green, showing the difference in resolution between 18x expansion (top; full field on left, zoom in orange on right) and 1000x expansion.

Fig. 1 Design of a four-network interpenetrating polymer network (IPN) architecture enabling ∼1000× linear expansion via recursive ionic-in-ionic casting.

Simple New System Keeps optical Microscopes in Focus Automatically and robustly

Good news!

"Now a team of scientists ... has developed an inexpensive robust fix for this problem that involves little more than a couple of LED lights and some physics-based processing. They describe the new autofocus technique, which they call Digital Defocus Aberration Interference (DAbI) ...

The underlying concept is fairly simple. When two LEDs illuminate a sample from slightly different angles, the combined signal derived from two photographs (one taken at each source of illumination) reveals a hidden fringe, or pattern of stripes. Those stripes change in a predictable way depending on how far the sample is from the focal point, the sweet spot where an image comes into focus. Therefore, a computer reading the stripes can tell the microscope how to correct for any blurriness in the image. ...

The scientists have tested DAbI on six different types of microscopes—from basic compound light microscopes to more complex systems used for imaging living cells and tissues, or even thick 3D specimens—all with excellent results. When dealing with thin flat samples, DAbI kept images in focus across a range more than 400 times larger than the natural depth of focus of a basic microscope lens. ... "This makes it useful and powerful for automated, high-throughput microscopy."

the DAbI technique is unique in that it can be used to locate the plane in which the focal point exists, even in thick 3D samples. Indeed, for thicker 3D samples up to 150 micrometers deep ..."

From the abstract:

"Automation in optical microscopy is critical for enabling high-throughput imaging across a wide range of biomedical applications. Among the essential components of automated systems, robust autofocusing plays a pivotal role in maintaining image quality for both single-plane and volumetric imaging.

However, conventional autofocusing methods often struggle with implementation complexity, limited generalizability across sample types, incompatibility with thick specimens, and slow feedback.

We observed that the digitally summed Fourier spectrum of two images acquired from two-angle illumination exhibits interference-like fringe modulation when the sample is defocused.

These digital fringes correlate directly with defocus through a physics-based relation.

Based on this principle, we developed an automatic, efficient, and generalizable defocus detection method termed digital defocus aberration interference (DAbI).

Implemented with a simple two-LED setup, DAbI can quantify the defocus distance over a range of 443 times the depth-of-field for thin samples and 296 times for thick specimens.

It can additionally extend the natural depth-of-field of the imaging system by 20-fold when integrated with complex-field imaging.

We demonstrated the versatile applications of DAbI on brightfield, complex-field, refractive index, confocal, and widefield fluorescence imaging, establishing it as a promising solution for automated, high-throughput optical microscopy."

Simple New System Keeps Microscopes in Focus Automatically - www.caltech.edu "Anyone who has ever used a microscope knows that it takes time to bring a sample into sharp focus. Each time you move the slide, the image blurs, and you have to stop and carefully turn a knob to bring everything back into clear view. For scientists and clinicians, even if the motion is semi-automated, that time quickly adds up as they work with dozens or hundreds of samples."

Digital defocus aberration interference for automated optical microscopy (open access of early version)

A schematic image of DAbI integration with an optical microscope setup.

Scientists capture superconductivity's 'dancing pairs' for first time, revealing missing pieces in a decades-old theory

Amazing stuff! 

What makes me wonder is that this study was done on atoms instead of electrons. What difference does it make going from electrons to atoms when it comes to superconductivity?

"For the first time, scientists have directly imaged the quantum process underlying superconductivity, a phenomenon in which paired electrons cause electric current to flow without resistance at sufficiently low temperatures. ...

the scientists directly imaged individual atoms pairing up in a special gas cooled nearly to absolute zero — the unreachable limit to how cold things can get. The type of gas, called a Fermi gas, allows scientists to substitute electrons with atoms and probe the physics of superconductors in a controlled way.

Surprisingly, the scientists found that after pairing up, the atoms moved in a synchronized dance, with their positions dependent on those of other pairs — a phenomenon not predicted by the 70-year-old, Nobel Prize-winning theory of superconductivity. ...

Using a newly developed imaging method, the experimental physicists captured snapshots of the relative positions of the pairs. The scientists used a special gas mixture made of lithium atoms, cooled to just a few billionths of a degree Celsius above absolute zero. At these temperatures, the atoms act as fermions, a fundamental class of particles that includes electrons. Since these fermions all follow the same physics of pairing, the atoms are suitable substitutes for studying electron behavior in superconductors.

The imaging revealed that the positions of paired atoms became influenced by those of other pairs. The paired atoms maintained a separation from other paired atoms, just as dancing couples keep their distance from other dancers in a ballroom ... This finding adds a new understanding of these systems that was missing from the historic BCS theory. ..."

"... From these observations, theorists have developed models—notably the Bardeen-Cooper-Schrieffer (BCS) theory, which assumes that the zero-resistance flow in a superconductor arises from electrons forming so-called Cooper pairs. This theory has been successful in explaining a large class of superconductors, but ... colleagues have now observed behavior that contradicts BCS predictions. Using a recently developed technique called atom-resolved continuum quantum gas microscopy, the researchers directly observed spatial correlations in cold atoms that mimic superconducting electrons. These high-precision measurements revealed an unexpected anticorrelation between opposite-spin atoms, implying deficiencies in the BCS theory. This and other surprising results demonstrate once again how new observational lenses can put long-standing theoretical models into question. ...

Predicting the collective behavior of electrons within materials is a formidable challenge. The many-body problem for classical particles is already difficult, but it is made unbelievably more complex for electrons and other fermions by the infamous “sign problem”: The wave function of fermionic particles changes sign upon particle exchange. This antisymmetric behavior gives rise to Pauli’s exclusion principle and makes modeling fermionic many-body systems incredibly challenging. ..."

From the abstract:

"In this Letter, we explore two-dimensional attractive Fermi gases at the microscopic level by probing spatial charge and spin correlations in situ.

Using atom-resolved continuum quantum gas microscopy, we directly observe fermion pairing and study the evolution of two- and three-point correlation functions as interspin attraction is increased.

The precision of our measurement allows us to reveal nonlocal anticorrelations in the pair correlation function, fundamentally forbidden by the mean-field result based on BCS theory but whose existence we confirm in exact auxiliary-field quantum Monte Carlo calculations.

We demonstrate that the BCS prediction is critically deficient not only in the superfluid crossover regime but also deep in the weakly attractive side.

Guided by our measurements, we find a remarkable relation between two- and three-point correlations that establishes the dominant role of pair correlations. Finally, leveraging local single-pair losses, we independently characterize the short-range behavior of pair correlations, via the measurement of Tan’s contact, and find excellent agreement with numerical predictions.

Our measurements provide a novel microscopic view into strongly correlated two-dimensional Fermi gases in the continuum."

Scientists capture superconductivity's 'dancing pairs' for first time, revealing missing pieces in a decades-old theory "Analysis of a first-of-its-kind experiment reveals missing pieces in the decades-old theory of superconductivity."

Scientists Capture Superconductivity’s ‘Dancing Pairs’ for First Time, Filling Gap in Decades-Old Theory (original news release) "Analysis of a first-of-its-kind experiment reveals missing pieces in the decades-old theory of superconductivity."

Superconductor Theory Under Cold-Atom Scrutiny "Snapshot measurements of cold-atom gases reveal hidden spin correlations that could force an update of some superconductivity theories."

Observing Spatial Charge and Spin Correlations in a Strongly Interacting Fermi Gas (no public access)

Figure 1: A continuum quantum gas microscope can image a 2D collection of cold atoms (left). In the case of a fermionic gas, the technique can differentiate between spin-up and spin-down atoms. Using the microscope data, researchers can compute the correlation function (right). The observations (solid orange line) disagree with the Bardeen-Cooper-Schrieffer theory (dashed yellow line) in that they show an anticorrelation “dip” for opposite spin atoms at a particular interparticle distance.

AI turns electron microscopy into materials insights in minutes

Good news! This could be an important breakthrough!

"... The EMSeek platform ... streamlines materials research by identifying key features in a microscopy image, determining the crystal structure, predicting material properties, comparing results with existing scientific literature and generating a report within a single, integrated workflow. ..."

From the abstract:

"Electron microscopy (EM) reveals atomic-scale structures that underpin catalysis, energy storage, and semiconductor reliability, yet current workflows remain fragmented across segmentation, crystallographic reconstruction, property modeling, and literature review, often requiring weeks of expert effort. Although recent artificial intelligence models have assisted individual steps, the diversity of EM modalities and tasks means existing approaches remain siloed and perform poorly in complex multistage workflows.

We present EMSeek, a modular, provenance-tracked multiagent platform that connects EM to materials insight through five key units: reference-guided one-for-all segmentation, mask-aware reconstruction of crystal structures from EM data, a gated mixture of experts property predictor with uncertainty calibration, literature retrieval with citation anchoring, and physical consistency checks with audit-ready reporting. These units are orchestrated by large language models (LLMs) that automatically plan, invoke, and execute tools, minimizing human intervention.

On 20 material systems and five tasks, EMSeek delivers segmentation about twice as fast as Segment Anything with higher accuracy, achieves more than 90% structural similarity on STEM2Mat, and, with about 2% labeled calibration, matches or surpasses strong single experts on three out-of-distribution property benchmarks.

A complete query runs in 2 to 5 minutes per image, roughly 50 times faster than expert workflows. Case studies on two-dimensional lattices and nanoparticles validate EMSeek’s ability to automate complex workflows, with integrated uncertainty calibration and audit signals that provide scientists with rigorous yet actionable guidance to accelerate materials discovery."

AI turns electron microscopy into materials insights in minutes | Cornell Chronicle

Bridging electron microscopy and materials analysis with an autonomous agentic platform (open access)

Fig. 1. Interactive EMSeek multiagent framework for end-to-end EM analysis.

Fig. 2. One-click reference-patch framework for universal EM segmentation.

Fig. 4. End-to-end agentic workflow linking EM images to materials knowledge.

Novel measurement confirms a 50-year-old prediction: Dark points are faster than light

Amazing stuff!

"A research group from the Technion-Israel Institute of Technology reports in Nature an unprecedented achievement in electron microscopy: the direct measurement of "dark points" within light waves. By doing so, the researchers were able to confirm a prediction from the 1970s that the speed of these points exceeds the speed of light. ..."

From the abstract:

"Phase singularities—points carrying quantized topological charge—are universal features found across diverse wave systems from superfluids and superconductors to acoustic and optical fields. Ensembles of these singularities exhibit distance correlations resembling particles in liquids, extensively studied for their role in exotic material phases. By contrast, the full correlations in phase space that govern the system evolution have remained unexplored and experimentally inaccessible.

Here we directly measure the ultrafast dynamics of optical singularity ensembles, capturing their full phase-space correlations, presenting the joint distance–velocity distribution.

Our observations show a breakdown of the particle-singularity analogy: phase singularities accelerate towards formally divergent velocities in the moment before annihilation, indicated by measurements of velocities exceeding the speed of light.

These apparent superluminal velocities are paradoxically amplified by the slow group velocity of hyperbolic phonon polaritons in our material platform, hexagonal boron nitride membranes. We demonstrate these phenomena using combined hardware and algorithmic advances in ultrafast electron microscopy, achieving spatial and temporal resolutions, each an order of magnitude below the polaritonic wavelength and cycle period. Our findings deepen our understanding of phase singularities and their universality, enabling to probe topological defect dynamics at previously unattainable timescales."

Novel measurement confirms a 50-year-old prediction: Dark points are faster than light

Superluminal correlations in ensembles of optical phase singularities (no public access)

A new clue to how the skin detects physical touch

Amazing stuff!

"... While scientists have long known that a protein called PIEZO2 acts as a key sensor for touch, it remained unclear why PIEZO2 is specialized for the localized mechanical forces experienced by sensory neurons, whereas its close relative PIEZO1 responds to broader mechanical stresses such as those generated when cells stretch, as occurs in blood vessels. 

Now, a new study  ... clarify how PIEZO2 detects specific types of force and explain why evolution may have selected it as the body’s primary sensor for light touch. This work may guide future exploration into sensory disorders linked to PIEZO2 mutations. ...

Although PIEZO1 and PIEZO2 appear nearly identical in molecular models, they behave very differently in living cells. PIEZO2 is especially important in the somatosensory nervous system, the network of nerve cells that detects touch. These cells are highly sensitive to small indentations, like a light tap on the skin. By contrast, PIEZO1 responds more readily to general membrane stretch, such as when a cell is pulled or swollen, rather than poked at a specific point.

To investigate the difference, the research team used minimal fluorescence photon flux (MINFLUX) super-resolution microscopy ... Whereas other imaging techniques, including cryogenic electron microscopy (cryo-EM), have captured detailed but static images of frozen PIEZO proteins that serve as references for overall shape, MINFLUX allows scientists to track the positions and movements of proteins in cells with nanometer-scale precision. ..."

From the abstract:

"PIEZOs are mechanically gated ion channels that transduce force into electrochemical signals.
PIEZO1 responds to diverse stimuli including membrane stretch2 and shear stress, whereas 

PIEZO2 is generally tuned to detect cellular indentation. The functional specialization of PIEZO2 is proposed to underlie its distinct physiological roles, including mediating the sense of touch. How PIEZO2 achieves this selectivity despite its close structural similarity to PIEZO1 is unclear.
Here we combine single-molecule MINFLUX fluorescence nanoscopy with electrophysiology to link the conformational states of PIEZO2 to channel gating in intact cells. We find that PIEZO2 is intrinsically more rigid than PIEZO1, and that disparate mechanical stimuli paradoxically evoke opposite conformational and gating responses in each channel.

These unique gating properties arise in part from a connection to the actin cytoskeleton, and we identify filamin-B (FLNB) as a molecular tether that is required for this interaction. This complex alters how force is transmitted to PIEZO2 and confers heightened sensitivity to and selectivity for cellular indentation. PIEZO2 and FLNB are co-expressed in somatosensory neurons and colocalize within tens of nanometres at the end organs of cutaneous mechanosensory afferents. These findings help to explain why PIEZO2 is a specialized mechanosensor and provide a molecular blueprint for understanding how cells decode diverse mechanical stimuli across tissues and organ systems."

A new clue to how the body detects physical force | Scripps Research

The molecular basis of force selectivity by PIEZO2 (open access)

Fig. 1: The divergent structural mechanics of PIEZO1 and PIEZO2 in a cell membrane.

Terahertz microscope reveals the motion of superconducting electrons

Amazing stuff!

"... Now, MIT physicists have used terahertz light to reveal inherent, quantum vibrations in a superconducting material, which have not been observable until now. ...

In a paper appearing today in the journal Nature, the scientists report that they have developed a new terahertz microscope that compresses terahertz light down to microscopic dimensions. This pinpoint of terahertz light can resolve quantum details in materials that were previously inaccessible. ..."

From the abstract:

"The superconducting gap defines the fundamental energy scale for the emergence of dissipationless transport and collective phenomena in a superconductor.

In layered high-temperature cuprate superconductors, in which the Cooper pairs are confined to weakly coupled two-dimensional (2D) copper–oxygen (CuO2) planes, terahertz (THz) spectroscopy at subgap millielectronvolt (meV) energies has provided crucial insights into the collective superfluid response perpendicular to the superconducting layers. However, within the CuO2 planes, the collective superfluid response manifests as plasmonic charge oscillations at energies far exceeding the superconducting gap, obscured by strong dissipation.

Here we present spectroscopic evidence of a below-gap, 2D superfluid plasmon in few-layer Bi2Sr2CaCu2O8+x and spatially resolve its deeply subdiffractive THz electrodynamics. By placing the superconductor in the near field of a spintronic THz emitter, we reveal this distinct resonance—absent in bulk samples and observed only in the superconducting phase—and determine its plasmonic nature by mapping the geometric anisotropy and dispersion. Crucially, these measurements offer a direct view of the momentum-dependent and frequency-dependent superconducting transition in two dimensions."

Terahertz microscope reveals the motion of superconducting electrons | MIT News | Massachusetts Institute of Technology "For the first time, the new scope allowed physicists to observe terahertz “jiggles” in a superconducting fluid."

Imaging a terahertz superfluid plasmon in a two-dimensional superconductor (no public access)

Imaging a terahertz superfluid plasmon in a two-dimensional superconductor (appears to be a preprint, open access)

New image sensor breaks optical limits without using lenses resolves sub-micron features at ultralong working distances and reconstructs 3D shapes over centimeter-scale fields

Amazing stuff! This could be a major breakthrough!

"... introducing a breakthrough solution that could redefine optical imaging across science, medicine, and industry.

"At the heart of this breakthrough is a longstanding technical problem," said Zheng. "Synthetic aperture imaging—the method that allowed the Event Horizon Telescope to image a black hole—works by coherently combining measurements from multiple separated sensors to simulate a much larger imaging aperture." ..."

"... Yet despite decades of innovation, a fundamental barrier has persisted: capturing high-resolution, wide-field images at optical wavelengths without cumbersome lenses or strict alignment constraints. ...

The Multiscale Aperture Synthesis Imager (MASI) turns this challenge on its head. Rather than forcing multiple optical sensors to operate in perfect physical synchrony – a task that would require nanometer-level precision – MASI lets each sensor measure light independently and then uses computational algorithms to synchronize the data afterward. ...

akin to having multiple photographers capture the same scene, not as ordinary photos but as raw measurements of light wave properties, and then letting software stitch these independent captures into one ultra-high-resolution image. ...

MASI deviates from conventional optical imaging in two transformative ways. Rather than relying on lenses to focus light onto a sensor, MASI deploys an array of coded sensors positioned in different parts of a diffraction plane. Each captures raw diffraction patterns –essentially the way light waves spread after interacting with an object. These diffraction measurements contain both amplitude and phase information, which are recovered using computational algorithms.

Once each sensor’s complex wavefield is recovered, the system digitally pads and numerically propagates the wavefields back to the object plane. A computational phase synchronization method then iteratively adjusts the relative phase offsets of each sensor’s data to maximize the overall coherence and energy in the unified reconstruction.

This step is the key innovation: by optimizing the combined wavefields in software rather than aligning sensors physically, MASI overcomes the diffraction limit and other constraints imposed by traditional optics.

The result? A virtual synthetic aperture for larger than any single sensor, enabling sub-micron resolution and wide field coverage without lenses. ..."

From the abstract:

"Synthetic aperture imaging has enabled breakthrough observations from radar to astronomy. However, optical implementation remains challenging due to stringent wavefield synchronization requirements among multiple receivers.

Here we present the multiscale aperture synthesis imager (MASI), which utilizes parallelism to break complex optical challenges into tractable sub-problems. MASI employs a distributed array of coded sensors that operate independently yet coherently to surpass the diffraction limit of single receiver. It combines the propagated wavefields from individual sensors through a computational phase synchronization scheme, eliminating the need for overlapping measurement regions to establish phase coherence.
Light diffraction in MASI naturally expands the imaging field, generating phase-contrast visualizations that are substantially larger than sensor dimensions.

Without using lenses, MASI resolves sub-micron features at ultralong working distances and reconstructs 3D shapes over centimeter-scale fields.

MASI transforms the intractable optical synchronization problem into a computational one, enabling practical deployment of scalable synthetic aperture systems at optical wavelengths."

New image sensor breaks optical limits

New Image Sensor Breaks Optical Limits (original news release) "UConn engineers develop new image sensor to achieve 3D microscopic resolution without lenses."

Multiscale aperture synthesis imager (open access)

A bullet cartridge imaged by MASI.
Top: The captured complex electric field contains both amplitude (brightness) and phase (color) information.
Bottom: This data enables 3D reconstruction at micrometer resolution, showing the firing pin impression, a unique marking that can link a bullet casing to a specific gun

Fig. 1: Operating principle and implementation of MASI.

Breakthrough microscope reveals real time flu virus cell invasion

Amazing stuff! What other pathogens can we now watch in action? This could be a breakthrough!

Will we soon have even better flu vaccinations?

"... On the surface of the influenza virus are two molecular "keys": hemagglutinin (HA) and neuraminidase (NA). They are the virus's lockpicks, the tools that let it slip into our cells and spread from one host to another.

The flu virus attacks much like a thief looking for unlocked doors. Its HA and NA proteins grab onto tiny molecules called sialic acids on the surface of cells. Once attached, the virus slides along the surface until the cell reshapes itself and swallows the virus inside. This process is called endocytosis.

But watching how the flu virus sneaks into cells has been difficult because standard microscopes can't capture these fast, tiny steps clearly.

In a breakthrough study, scientists from Switzerland and Japan built a new kind of "super microscope" by blending two powerful imaging tools: atomic force microscopy (AFM) and fluorescence microscopy, creating a new method called virus-view dual confocal and AFM (ViViD-AFM). This hybrid system lets researchers zoom in on living human cells with incredible detail. This offers a new real time insight into how the flu virus operates.

For the first time, researchers could actually see the nanoscale drama of influenza invading a cell. But what surprised them most was the target cell's role in this process. Instead of sitting quietly and letting the virus in, the cell seemed to fight back: stretching, shifting, and even trying to grab hold of the virus as if to control the encounter. "The infection of our body cells is like a dance between virus and cell," ...

With their new system, the team watched how single flu virus particles move across the surface of a cell under different conditions, like when specific viral proteins were blocked, when fewer binding sites were available on the cell, or when different virus types were tested. They also studied how the cell's membrane changes shape before and during the virus's entry. ..."

From the significance and abstract:

"Significance

Influenza A viruses (IAVs) continue to cause epidemics worldwide due to their high mutability. Nevertheless, the initial step of infection, viral uptake into cells, has been challenging to observe directly with conventional microscopy techniques. Here, we developed a hybrid imaging system combining atomic force microscopy and confocal microscopy with enhanced mechanical functionality and minimal invasiveness to directly visualize nanoscale dynamics of IAV and cell membranes during viral uptake into living cells. This system enables the analysis of IAV lateral diffusion resulting from IAV–membrane interactions and characteristic membrane morphological changes induced by IAV during endocytosis. Our approach offers a method to rapidly assess the impact of viral mutations on host cell entry, which is critical for understanding emerging IAV variants.

Abstract

Influenza A virus (IAV) entry into host cells begins with interactions between the viral envelope proteins hemagglutinin (HA)/neuraminidase (NA) and sialic acid moieties on the cell plasma membrane.

These interactions drive IAV’s lateral diffusion along the cell membrane and trigger membrane morphological changes required for endocytosis. However, directly visualizing these dynamic processes, which are crucial for IAV entry, has been challenging using conventional microscopy techniques.

In this study, we enabled live-cell observation of nanoscale morphological dynamics of IAV and the cell membrane by reducing the mechanical invasiveness of atomic force microscopy (AFM).

A customised cantilever with less than half the spring constant of conventional cantilevers enabled virus-view AFM imaging that preserved IAV–membrane interactions.

By combining virus-view AFM with confocal microscopy, we performed correlative morphological and fluorescence observations of IAV lateral diffusion and endocytosis in living cells.

Variations in diffusion coefficients of single virions suggested heterogeneity in sialic acid density on the cell membrane. NA inhibition decreased diffusion coefficients, while reduced sialic acid density increased them.

The timing of clathrin accumulation at virion binding sites coincided with a decrease in diffusion coefficients, a relationship that was maintained independent of NA activity or sialic acid density. As clathrin assembly progressed, ~100-nm-high membrane bulges emerged adjacent to the virus, culminating in the complete membrane envelopment of the virus at peak clathrin accumulation.

Our virus-view AFM will deepen our understanding of various virus–cell interactions, facilitate the evaluation of drug effects and promote future translational research."

Breakthrough microscope reveals real time flu virus cell invasion

How influenza viruses enter our cells (original news release) "For the first time, researchers have observed live and in high resolution how influenza viruses infect living cells. This was possible thanks to a new microscopy technique, which could now help to develop antiviral therapies in a more targeted manner. "

Enhanced visualization of influenza A virus entry into living cells using virus-view atomic force microscopy (open access)

Fig. 4 Membrane bulges cover virus particles during IAV CME. 

Latest advances in super-resolution optical microscopy to the level of individual atoms. Really!

Amazing stuff! This approach may seem to be a little bit to clever when you need to know the material's atomic configuration in advance! May this not defeat the purpose of discovery by microscopy? Is it a form of  bootstrapping?

Even the name of this new approach, i.e.  discrete grid imaging technique or DIGIT, suggests it is relying on the or presuming a grid structure of crystals. However, what if the grid is a fiction or invalid abstraction to some extent?

"... Only recently have scientists found ways to break this “diffraction limit,” to see features that are smaller than the wavelength of light. With new techniques known as super-resolution microscopy, scientists can see down to the scale of a single molecule. ...

scientists present a new computational method that enables optical microscopes to resolve individual atoms and zero in on their exact locations in a crystal structure.

The team’s new “discrete grid imaging technique,” or DIGIT, is a computational imaging approach that scientists can apply to optical data to calculate the most probable location of individual atoms based on a very important clue: the material’s known atomic configuration. As long as scientists have an idea of what a material’s physical atomic layout should be, they can use this layout as a sort of map to determine where specific atoms or features must be located. ...

With DIGIT, the team can now pinpoint individual atoms with a resolution of 0.178 angstroms. ... The technique enables optical microscopes to localize atomic-scale features in any material that has a known atomic pattern, such as crystalline materials or certain proteins with repeating molecular chains. ..."

From the abstract:

"Super-resolution microscopy has revolutionized the imaging of complex physical and biological systems by surpassing the Abbe diffraction limit. Recent advancements, particularly in single-molecule localization microscopy, have pushed localization below nanometer precision, by applying prior knowledge of correlated fluorescence emission from single emitters.

However, achieving a refinement from 1 nm to 1 Ångström demands a hundred-fold increase in collected photon signal. This quadratic resource scaling imposes a fundamental barrier in single-molecule localization microscopy, where the intense photon collection is challenged by photo-bleaching, prolonged integration times, and inherent practical constraints.

Here, we break this limit by harnessing the periodic nature of the atomic lattice structure. Applying this discrete grid imaging technique (DIGIT) in a quantum emitter system, we observe an exponential collapse of localization uncertainty once surpassing the host crystal’s atomic lattice constant. We further applied DIGIT to a large-scale quantum emitter array, enabling parallel positioning of each emitter through wide-field imaging. Collectively, these advancements establish DIGIT as a competitive tool for achieving unprecedented, precise measurements, ultimately paving the way to direct optical resolution of crystal and atomic features within quantum and biological systems."

A “seating chart” for atoms helps locate their positions in materials | MIT News | Massachusetts Institute of Technology

A Bayesian approach towards atomically-precise localization in fluorescence microscopy (open access)

Fig. 1: DIGIT concept.

Flexible fitting method translates high-speed atomic force microscopy images into precise protein motion models

Good news!

"High-speed atomic force microscopy (HS-AFM) is the only experimental technique to directly watch proteins in dynamic action. However, as a surface scanning technique with limited spatial resolution, HS-AFM will inevitably provide insufficient information for detailed atomistic understanding of biomolecular function. Despite previous efforts in computational modeling attempting to overcome such limitations, successful applications to retrieve atomistic-level information from measurements are practically absent.

A research team ... presents a computational framework and its software implementation allowing to infer 3D atomistic models of dynamic protein conformations from AFM topography imaging. ..."

From the abstract:

"High-speed atomic force microscopy (HS-AFM) experiments allow direct observation of biomolecular dynamics at the single-molecule level, acquiring a large amount of topographic imaging data that visualizes changes in the molecular surface during functional activity over an extended period of time. Since images have no atomistic resolution, a major challenge has been to develop post-experimental computational methods to infer atomistic information from measurements.

The recently developed NMFF-AFM flexible fitting method provides a computationally efficient approach promising to infer atomistic-precision models of conformational dynamics from resolution-limited AFM imaging data.

We report the software integration of this method into the well-established BioAFMviewer platform and demonstrate its first applications to experimental HS-AFM imaging data.

To facilitate applications, we developed a direct workflow from raw experimental AFM data to the visualization and analysis of fitting results. The presented applications to experimental data of a single protein domain, a protein complex, and a megadalton-sized protein filament demonstrate the versatility of NMFF-AFM modeling to reproduce large-amplitude conformational motions of biomolecular dynamics from HS-AFM imaging. 

As a first step toward automated large-scale analysis of AFM imaging data, we furthermore demonstrate reconstruction of an atomistic molecular movie of protein dynamics, involving large-amplitude conformational transitions, from a measured HS-AFM movie sequence.

Implementation of flexible fitting within the stand-alone user-friendly interactive BioAFMviewer software provides the opportunity for a broad range of applications to facilitate the understanding of resolution-limited HS-AFM measurements."

Flexible fitting method translates high-speed atomic force microscopy images into precise protein motion models

Flexible Fitting to Infer Atomistic-Precision Models of Large-Amplitude Conformational Dynamics in Biomolecules from High-Speed Atomic Force Microscopy Imaging (open access)

Graphical abstract

Figure 2. HECT domain large-amplitude conformational transition. 

High-speed 3D imaging with a 25-camera multifocus microscope capturing movement of living samples

Amazing stuff!

"... So researchers designed a moving-picture system [M25] that can mount to the side port of a standard commercial microscope: an array of 25 miniature cameras, each capturing the same image simultaneously but at different depths. A specially designed, multi-focus grating made of nanometer-etched glass splits the light evenly into each camera, and more gratings in front of each lens correct any oddities ...

To test M25, researchers imaged live model organisms like a nematode and fly and oyster parasite larvae, finding that it could capture organisms up to 50 micrometers deep. Importantly, the microscope could capture fluorescent and non-fluorescent samples, so it doesn’t require invasive marking techniques that can damage samples. In the video above, the cameras capture a wormy nematode subject wriggling and writhing. ..."

From the abstract:

"High-speed volumetric imaging of whole-organism dynamics is often constrained by trade-offs between speed, resolution, and imaging depth. We present the M25 microscope, a 25-camera-array, aberration-corrected refocusing multifocus imaging system that captures 3D volumes simultaneously across 25 focal planes using a synchronized array of machine-vision cameras. Each camera incorporates a custom-blazed grating to correct chromatic dispersion, enabling a simplified, sensitive, and scalable multifocus setup for large fields of view while maintaining high spatial resolution across the imaging volume.

M25 achieves imaging speeds of volumes per second over imaging volumes of µ. This method enables both noninvasive, label-free brightfield and highly sensitive fluorescence imaging.

We demonstrate its capabilities in 3D particle tracking, fluorescent and brightfield imaging of D. melanogaster larval dynamics, and C. elegans locomotion and neural activity. This method enables fast and sensitive 3D imaging for biological studies and has potential applications across a broad range of diffractive imaging modalities."

ScienceAdviser

Multifocus microscope pushes the limits of fast live 3D biological imaging "Using 25 cameras to capture detailed dynamics, the new system extends classical multifocus microscopy to study development, locomotion, and neuroscience in real time"

High-speed 3D imaging with a 25-camera multifocus microscope (open access)

Fig. 1. Aberration-corrected refocusing with 25-plane camera-array multifocus microscope (M25).

Atom-by-atom imaging of moiré phasons or atomic thermal vibrations at a resolution of under 15 picometers

Amazing stuff! Good vibrations!

"A pioneering team ... has captured the first-ever images of atomic thermal vibrations, unlocking an unseen world of motion within two-dimensional materials. Their innovative electron ptychography technique revealed elusive “moiré phasons,” a long-theorized phenomenon that governs heat, electronic behavior, and structural order at the atomic level. This discovery not only confirms decades-old theories but also provides a new lens for building the future of quantum computing, ultra-efficient electronics, and advanced nanosensors. ..."

"Researchers investigating atomic-scale phenomena impacting next-generation electronic and quantum devices have captured the first microscopy images of atomic thermal vibrations—revealing a new type of motion that could reshape the design of quantum technologies and ultrathin electronics. ...

developed an electron microscopy technique to directly image “moiré phasons”—a physical phenomenon that impacts superconductivity and heat conduction in two-dimensional materials for next-generation electronic and quantum devices. ..."

From the abstract of the perspective:

"Twisted heterostructures—two atomically thin layers stacked at an angle by van der Waals forces—exhibit exotic properties beyond those of each layer alone, such as superconductivity.

The interlayer interactions cause structural reconstruction of atoms within the layers, forming a Moiré superlattice. This lattice has distinctive vibrational modes, called Moiré phonons (or phasons), that affect the material’s properties. However, low energy (~0.01 meV) and nanometer-scale spatial variation make the characterization of phasons with existing techniques extremely challenging. ...

Zhang et al. report the use of a computational imaging technique, called electron ptychography, to characterize phasons in twisted bilayers of tungsten diselenide. The findings illustrate how the extreme spatial resolution offered by electron ptychography can yield insights into a phenomenon that would be otherwise difficult to study."

From the editor's summary and abstract:

"Editor’s summary

The collective vibrations of a low-twist-angle moiré superlattice of tungsten diselenide were imaged with high-resolution electron ptychography. The rotationally aligned regions in these superlattices are separated by networks of stacking faults that can host ultrasoft shear modes, or phasons, with frequencies less than one wavenumber that are inaccessible using conventional vibrational spectroscopy. Imaging by Zhang et al. at a resolution of under 15 picometers revealed that these spatially localized, anisotropic vibrations dominated the thermal vibrations ...

Abstract

Twisted two-dimensional materials exhibit distinctive vibrational modes called moiré phonons, which arise from the moiré superlattice.

Here, we demonstrate atom-by-atom imaging of phasons, an ultrasoft class of moiré phonons in twisted bilayer tungsten diselenide (WSe2).

Using ultrahigh-resolution (<15 picometers) electron ptychography, we imaged the size and shape of each atom to extract time-averaged vibrational amplitudes as a function of twist angle and position.

We observed several signature properties of moiré phasons, such as increased vibrational amplitudes at solitons and AA-stacked regions. By correlating experiments with molecular dynamics simulations and lattice dynamics calculations, we show that phasons dominate the thermal vibrations in low-angle twisted bilayers. These results represent a powerful route to image thermal vibrations at atomic resolution, unlocking experimental studies of a thus far hidden branch of moiré phonon physics."

You’ve never seen atoms like this before: A hidden motion revealed | ScienceDaily

Scientists Document First Images of the Atomic Fingerprint of Heat in Quantum Materials (original news release)

Minuscule vibrations, uncovered (no public access) "Computational imaging resolves atomic vibrations at picometer scale"

Atom-by-atom imaging of moiré phasons with electron ptychography (no public access)

Atom-by-atom Imaging of Moiré Phasons using Electron Ptychography (preprint, open access)

The lead author Yichao Zhang