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Self-consistent theory of many-body localisation in a quantum spin chain with long-range interactions

by Sthitadhi Roy, David E. Logan

Submission summary

As Contributors: Sthitadhi Roy
Arxiv Link: https://arxiv.org/abs/1903.04851v1
Date submitted: 2019-03-22
Submitted by: Roy, Sthitadhi
Submitted to: SciPost Physics
Domain(s): Theoretical
Subject area: Condensed Matter Physics - Theory

Abstract

Many-body localisation is studied in a disordered quantum spin-1/2 chain with long-ranged power-law interactions, and distinct power-law exponents for interactions between longitudinal and transverse spin components. Using a self-consistent mean-field theory centring on the local propagator in Fock space and its associated self-energy, a localisation phase diagram is obtained as a function of the power-law exponents and the disorder strength of the random fields acting on longitudinal spin-components. Analytical results are corroborated using the well-studied and complementary numerical diagnostics of level statistics, entanglement entropy, and participation entropy, obtained via exact diagonalisation. We find that increasing the range of interactions between transverse spin components hinders localisation and enhances the critical disorder strength. In marked contrast, increasing the interaction range between longitudinal spin components is found to enhance localisation and lower the critical disorder.

Current status:
Editor-in-charge assigned

Submission & Refereeing History

Submission 1903.04851v1 on 22 March 2019

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