Paper accepted by NPG Asia Mater:Normal-to-topological insulator martensitic phase transition in group-IV monochalcogenides driven by light
Owing to the pursuit of ultrafast and efficient store and reading information in the next generation nanodevices, topological materials are attracting tremendous attention during the past decade. Usually, a topologically trivial material may transit into nontrivial under electrostatic field and hydrostatic pressure. Such topological phase transition is intriguing since it cannot fall into classical Fermi liquid theory. For the first time, Prof. Jian Zhou at CAMP-Nano, collaborated with Prof. Shunhong Zhang at USTC and Prof. Ju Li at MIT, predicted that a topological phase transition could occur under laser pulse illumination. They use SnSe as an exemplary material of group IV-VI semiconductors and apply thermodynamic theory to reveal such process. The Pnma-SnSe with a large figure of merit thermoelectric feature could transform into Fm-3m phase, which is topological crystalline insulating, with a barrierless kinetics. By changing the optical frequency, the Fm-3m phase could go back to Pnma phase. A promising opto-caloric effect is also proposed. This novel opto-mechanical approach can be applied into multiple materials and provide a noncontacting and noninvasive strategy to control the materials’ geometry.
LINK:
https://www.nature.com/articles/s41427-019-0188-9
