2019/12/31 by Nilanjan Roy, Ajith Ramachandran, Auditya Sharma
Chemistry · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Anderson localization #Chain (unit) #Diamond #Eigenvalues and eigenvectors #Non-equilibrium thermodynamics #Phase (matter) #Quantum many-body systems #Topological Materials and Phenomena #cond-mat.dis-nn #cond-mat.quant-gas #cond-mat.str-el
paper · pdf · doi:10.1103/physrevresearch.2.043395
published as Phys. Rev. Research 2, 043395 (2020) · 16 pages, 29 figures (Appendix included)
openalex publication_date 2020/12/21 · arxiv created 2020/12/23 · arxiv updated 2020/12/24 · openalex created_date 2021/01/05 · openalex updated_date 2026/08/05
We 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 conventional Anderson localization (AL). The compactly localized (CL) eigenstates of flat bands show a persisting oscillatory recurrence in the study of single-particle wave-packet dynamics. For low disorder, a damped oscillatory recurrence behavior is observed which is absent for high disorder. Noninteracting many-particle fermion states also follow the same trend except showing a delocalizing tendency at intermediate disorder due to the fermionic statistics in the system. 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.