Amazing stuff!
"... By switching from insulating to conducting and vice versa, the discovery creates the potential to replace silicon components in electronics with exponentially smaller and faster quantum materials.
"Processors work in gigahertz right now," ... "The speed of change that this would enable would allow you to go to terahertz."
Via controlled heating and cooling, a technique they call "thermal quenching," researchers are able to make a quantum material switch between a metal conductive state and an insulating state. These states can be reversed instantly using the same technique. ..."
From the abstract:
"Ultrafast light–matter interaction has emerged as a mechanism to control the macroscopic properties of quantum materials. However, technological applications of photoinduced phases are limited by their ultrashort lifetimes and the low temperatures required for their stabilization.
One such phase is the hidden metallic charge density wave state in 1T-TaS2 [1T phase tantalum disulfide], whose origin and stability above cryogenic temperatures remain the subject of debate. Here, we demonstrate that this phase can be stabilized at thermal equilibrium by accessing a mixed charge density wave order regime through thermal quenching. Using X-ray high-dynamic-range reciprocal space mapping and scanning tunnelling spectroscopy, we reveal the coexistence of commensurate charge density wave and hidden metallic charge density wave domains up to 210 K.
Our findings show that each order parameter breaks basal plane mirror symmetry with different chiral orientations and induces out-of-plane unit cell tripling in the hidden phase. Despite metallic domain walls and a finite density of states, the bulk resistance remains insulating due to charge density wave stacking disorder. Our results establish the hidden state as a thermally stable phase and introduce an alternative mechanism for switchable metallic behaviour in thin flakes of 1T-TaS2 and similar materials with competing phases."
Dynamic phase transition in 1T-TaS2 via a thermal quench (no public access)
Dynamic phase transition into a mixed-CDW state in 1-TaS via a thermal quench (this appears to be the preprint, open access)
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