Multifractality in the interacting disordered Tavis-Cummings model
We analyze the spectral and transport properties of the interacting disordered Tavis-Cummings model at half excitation filling. We demonstrate that a Poissonian-level statistics coexists with eigenfunctions that are multifractal (extended, but nonergodic) in the Hilbert space, for all strengths of light-matter interactions. This is associated with a lack of thermalization for a local perturbation. We find that the bipartite entanglement entropy grows logarithmically with time, similarly to many-body localized systems, while the spin imbalance tends to zero for strong coupling, in analogy to ergodic phases. We show that these effects are due to the combination of finite interactions and integrability of the model. When a small integrability-breaking perturbation (nearestneighbor hopping) is introduced, typical eigenfunctions become ergodic, seemingly turning the system into a near-perfect conductor, contrary to the single-excitation noninteracting case. We propose a realization of this model with cold atoms.
WOS:001198594600005
2024-02-08
109
6
064202
REVIEWED
Funder | Grant Number |
French National Research Agency under the Investments of the Future Program | ANR-21-ESRE-0032 |
ECOS-CONICYT | C20E01 |
Centre National de la Recherche Scientifique (France) through the IEA 2020 campaign | |
Swiss National Science Foundation | 184654 |
Swiss State Secretariat for Education, Research and Innovation | MB22.00063 |