Interplay of disorder and interactions in the bilayer band insulator: A determinant quantum Monte Carlo study

Prasad, Y and Lee, H (2024) Interplay of disorder and interactions in the bilayer band insulator: A determinant quantum Monte Carlo study. In: Physical Review B, 109 (6).

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Abstract

In previous studies of the half-filled bilayer attractive Hubbard model Prasad, Phys. Rev. A 89, 043605 (2014)1050-294710.1103/PhysRevA.89.043605; Prasad, Phys. Rev. B 106, 184506 (2022)2469-995010.1103/PhysRevB.106.184506, it has been shown that the clean system has a band-insulator (BI) to superfluid (SF) quantum phase transition. In this paper, we append the effects of random on-site disorder on the kinetic energy, double occupancy, and the pair-pair correlations in the bilayer model. Using the determinant quantum Monte Carlo simulation, we observe that the on-site random disorder plays a significant role in the localization of on-site pairs, and hence in the reduction of the effective hopping. This results in an increase of the double occupancy, which is an effect that is similar to the attractive interaction. We find no change in the critical value of the interaction at which the model undergoes a transition from the BI to SF regime, even though the pair-pair correlations get suppressed for finite on-site disorder strengths Vd/t=0.1-0.8. We also confirm that the weak-disorder suppresses the SF phase largely in the strong-coupling limit. Hence the region of the SF phase reduces in the presence of random on-site disorder. Finally, through finite-size scaling, we have estimated the critical disorder strength Vdc/t�1.44 at |U|/t=5. © 2024 American Physical Society.

Item Type:	Journal Article
Publication:	Physical Review B
Publisher:	American Physical Society
Additional Information:	The copyright for this article belongs to Author.
Keywords:	Hubbard model; Intelligent systems; Kinetics; Monte Carlo methods; Phase transitions; Quantum theory, Band insulators; Bi-layer; Clean systems; Disorder strength; Pair correlations; Quantum Monte Carlo simulations; Quantum monte carlo studies; Quantum-phase transition; Site disorder; Superfluid phasis, Kinetic energy
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	04 Apr 2024 12:03
Last Modified:	04 Apr 2024 12:03
URI:	https://eprints.iisc.ac.in/id/eprint/84711

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