Amazing stuff!
"A new study by ... physicists sheds light on how two different phases of electron behavior can emerge and coexist in the same quantum material.
Their results ... can help explain how some materials host superconductivity, magnetism and other electronic phases. Untangling such phases and understanding how they emerge will help engineers control electronic behavior and design high-performance quantum devices. ...
Now, ... have teased apart erbium tritelluride's phases and observed how each phase emerges. They found that one phase forms gradually, similar to how liquid water transitions uniformly into vapor. This is the classic, textbook way in which electronic phase transitions are thought to occur.
But the second phase came about in an entirely new and unexpected way: Instead of emerging gradually, the electrons organized first in pockets that eventually expanded, similar to how liquid water crystallizes into ice. ...
Scientists have observed charge density waves for decades, most recently in materials that also host other, more complicated forms of electron coordination, such as various forms of magnetism and superconductivity, in which electrons pair up and flow through a material without friction.
"Just like superconductivity, charge density waves are a collective phenomenon in which electrons move together in certain ways," ... "The power of CDWs is that they are a much simpler form of matter compared to superconductivity. They offer a playground for fundamental understanding." ..."
From the abstract:
"Understanding the origin of phase transitions and the interactions between distinct phases remains a central task in condensed-matter physics.
Charge-density-wave (CDW) systems provide a useful setting to investigate these questions. Although the dominant CDW phases in many materials can be explained through electron–phonon interactions, certain CDW phase transitions remain poorly understood, challenging conventional paradigms.
One example is the rare-earth tritelluride ErTe3, which hosts two competing CDW orders. Although electron–phonon coupling accounts for the dominant order, the mechanism behind the subdominant order remains unclear.
In this study, we combine time- and angle-resolved photoemission spectroscopy and time-dependent Ginzburg–Landau theory to establish a time-domain approach for probing phase transitions in solid-state systems.
By analysing the distinct recovery dynamics of the two CDW orders in ErTe3 following light excitation, we reveal a novel nucleation and growth mechanism that probably drives the secondary CDW phase transition.
More broadly, this work provides a time-domain framework for studying phase transitions and phase competition in quantum materials."
Physicists watch a material’s electrons assemble, and reassemble, into coexisting phases (original news release) "The study could help scientists understand how superconductivity and other more complex phenomena emerge in quantum materials"
Time-domain identification of distinct mechanisms for competing charge density waves in a rare-earth tritelluride (no public access)
Time-domain identification of distinct mechanisms for competing charge density waves in a rare-earth tritelluride (preprint, open access, a very short paper with only 9 pages)
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