Workshop on Electronic Crystals ECRYS-2022

The International School and Workshop on Electronic Crystals ECRYS-2022 is a tri-annual conference series  which have been running  in France since 1993. The  meeting  will be host by the Institute of Scientific Studies in Cargese, Corsica, France  (Institut d’Etudes Scientifiques de Cargèse) from the 8th to the 22nd of August 2022. The conference puts together lectures by leading scientists with seminars by young scientists.

Massimo Rontani will present MoS₂ and monolayer WTe₂ as ideal Excitonic Insulators as an invited speaker.

It will be shown that MoS₂ under pressure and monolayer WTe₂ are Excitonic Insulators. A surge of experimental claims has recently addressed layered materials, because of reduced Coulomb screening. However, the transition to the putative EI is ubiquitously accompanied by the softening of a phonon inducing a structural change; therefore it remains unclear whether the observed phase is genuinely excitonic or instead stabilized by electron–phonon interaction. Calculations from first principles show that MoS₂ for a range of applied pressure is unstable against the spontaneous generation of excitons but stable against lattice distortion. Furthermore, theoretical and experimental evidence that the two-dimensional bulk of monolayer WTe₂ contains excitons that spontaneously form in thermal equilibrium will be presented.