Many-body localization in the interpolating Aubry-André-Fibonacci model

Abstract

We investigate the localization properties of a spin chain with an antiferromagnetic nearest-neighbour coupling, subject to an external quasiperiodic on-site magnetic field. The quasiperiodic modulation interpolates between two paradigmatic models, namely the Aubry-André and the Fibonacci models. We find that stronger many-body interactions extend the ergodic phase in the former, whereas they shrink it in the latter. Furthermore, the many-body localization transition points at the two limits of the interpolation appear to be continuously connected along the deformation. As a result, the position of the many-body localization transition depends on the interaction strength for an intermediate degree of deformation of the quasiperiodic modulation. Moreover, in the region of parameter space where the single-particle spectrum contains both localized and extended states, many-body interactions induce an anomalous effect: weak interactions localize the system, whereas stronger interactions enhance ergodicity. We map the model's localization phase diagram using the decay of the quenched spin imbalance in relatively long chains. This is accomplished employing a time-dependent variational approach applied to a matrix product state decomposition of the many-body state. Our model serves as a rich playground for testing many-body localization under tunable potentials.

13 pages, 9 figures, comments are welcome

References in corpus (12)

• Many body localization and thermalization in quantum statistical mechanics
• Localization of interacting fermions at high temperature
• Real time evolution using the density matrix renormalization group
• The distribution of the ratio of consecutive level spacings in random matrix ensembles
• Many body localization in Heisenberg XXZ magnet in a random field
• Many-Body Localization in a Quasiperiodic System
• Nearest neighbor tight binding models with an exact mobility edge in one dimension
• Observation of Topological Phase Transitions in Photonic Quasicrystals
• Topological Pumping over a Photonic Fibonacci Quasicrystal
• Marginal Anderson localization and many body delocalization
• Stark many-body localization: Evidence for Hilbert-space shattering
• A mean-field theory of nearly many-body localized metals

Cited by in corpus (2)

• Quantum criticality and universality in the $p$-wave paired Aubry-André-Harper model
• Many-body localization in a tilted potential in two dimensions