Scientists observe exotic superradiant quantum phase once thought impossible

Amazing stuff!

"A team ... researchers reported the first direct observation of a surprising quantum phenomenon predicted over half a century ago, opening pathways for revolutionary applications in quantum computing, communication, and sensing.

Known as a superradiant phase transition (SRPT), the phenomenon occurs when two groups of quantum particles begin to fluctuate in a coordinated, collective way without any external trigger, forming a new state of matter.

The discovery was made in a crystal composed of erbium, iron, and oxygen that was cooled to minus 457 Fahrenheit and exposed to a powerful magnetic field of up to 7 tesla (over 100,000 times stronger than Earth's magnetic field) ..."

From the abstract:

"Two-level atoms ultrastrongly coupled with single-mode cavity photons are predicted to exhibit a quantum phase transition, entering a phase in which both the atomic polarization and the photonic field are finite even without external driving.

However, this phenomenon, the superradiant phase transition (SRPT), is forbidden by a no-go theorem due to the existence of the diamagnetic term.

Here, we present spectroscopic evidence for a magnonic SRPT in ErFeO3, where the role of the photonic mode (two-level atoms) in the photonic SRPT is played by an Fe3+ magnon mode (Er3+ spins). 

The absence of the diamagnetic term in the Fe3+-Er3+ exchange coupling ensures that the no-go theorem does not apply.

Ultrabroadband terahertz and gigahertz magnetospectroscopy experiments revealed the signatures of the SRPT in thermal equilibrium, a kink and a softening, respectively, of two spin-magnon hybridized modes at the critical point.

Systems near this phase are expected to harbor large-scale squeezing, which will potentially provide a route to next-generation quantum technologies."

Scientists observe exotic quantum phase once thought impossible

Scientists observe exotic quantum phase once thought impossible (original news release) "Discovery in a magnetic crystal could enable breakthroughs in quantum tech"

Observation of the magnonic Dicke superradiant phase transition (open access)

Fig. 1. Comparison between a light-matter system and a magnon-spin system for the Dicke SRPT.

Fig. 2. Spectroscopic evidence for the magnonic SRPT in ErFeO3.

The amino acid tryptophan can exhibit a quantum phenomenon called superradiance and the computational limits of life

Amazing stuff!

"... scientists have traditionally assumed that biology and quantum mechanics just don’t mix. After all, living systems are warm and unpredictable, and even itty-bitty cells are far too large to display quantum properties. But last year, a team of researchers ... demonstrated that the amino acid tryptophan can exhibit a quantum phenomenon called “superradiance” when arranged in large networks within cells. That discovery ... could mean that life on Earth has far more computing capacity than previously thought.

Because all life forms are physical systems and process information according to the laws of physics, they can be thought of as performing computations. When estimating the computational limits of life, scientists have traditionally treated the neuron as the fundamental information-processing unit. But many organisms that lack neurons—including bacteria, fungi, and plants—are still capable of performing computations. ... these life forms have been around much longer than animals, making them responsible for the vast majority of carbon-based computation on Earth.

The discovery of superradiant quantum effects in proteins containing tryptophan, meanwhile, suggests that living cells can process information much more efficiently than previously thought. These tryptophan networks could even be operating as quantum fiber optics, allowing cells across the tree of life to process information billions of times faster than traditional biochemical signaling would allow—rivaling the power of even the most sophisticated quantum computers. ..."

From the abstract:

"As physical systems, all life in the universe processes information according to physical laws. Estimates for the computational capacity of living systems generally assume that the fundamental information-processing unit is the Hodgkin-Huxley neuron, thereby excluding aneural organisms. Assuming the laws of quantum mechanics, the relativistic speed limit set by light, a universe at critical mass-energy density, and a recent experimental demonstration of single-photon superradiance in cytoskeletal protein fibers at thermal equilibrium, it is conjectured that the number of elementary logical operations that can have been performed by all eukaryotic life in the history of Earth, which is shown to be approximately equal to the ratio of the age of the universe to the Planck time, is about the square root of the number by the entire observable universe from the beginning. The existence of ultraviolet-excited states in these protein fibers, operating within two orders of magnitude of the Margolus-Levitin speed limit, motivates state-of-the-art performance comparisons with contemporary quantum computers."

ScienceAdviser

Howard University physicist revisits the computational limits of life and Schrödinger’s essential question in the era of quantum computing "The discovery of life processing with UV-excited qubits supports a conjecture relative to the computing capacity of the universe"

Computational capacity of life in relation to the universe (open access)