1. interplay of disorder and interactions in a flat-band supporting diamond chain

Auditya Sharma

Indian Institute of Science Education and Research, Bhopal, India

23 February 2021 Tue 5 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

We [1] systematically study the effect of disorder and interactions on a quasi- one-dimensional diamond chain possessing flat bands. Disorder localizes all the single-particle eigenstates. While at low disorder strengths, we obtain weak flat-band based localization (FBL), at high disorder strengths, we see conven- tional Anderson localization (AL). We also show how the study of noninteracting many-particle fermion states offers fresh insights. As interactions are switched on, for the finite sizes that we are able to study, a nonergodic mixed phase is observed at low disorder which is separated from the MBL phase at high disorder by a thermal phase at intermediate disorder. A study of many-body nonequilibrium dynamics reinforces these findings.


[1] Nilanjan Roy, Ajith Ramachandran, and Auditya Sharma. Interplay of disorder and interactions in a flat-band supporting diamond chain. Phys.Rev.Research 2, 043395 (2020).