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arXiv · 1611.00047

A correlated Anderson insulator on the honeycomb lattice

Tianxing Ma·Lufeng Zhang·Chia-Chen Chang·Hsiang-Hsuan Hung·Richard T. Scalettar
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Abstract

We study the effect of disorder on the semimetal -- Mott insulator transition in the half-filled repulsive Hubbard model on a honeycomb lattice, a system that features vanishing density of states at the Fermi level. Using the determinant quantum Monte Carlo method, we characterize various phases in terms of the bulk-limit antiferromagnetic (AF) order parameter, compressibility, and temperature-dependent DC conductivity. In the clean limit, our data are consistent with previous results showing a single quantum critical point separating the semi-metallic and AF Mott insulating phases. With the presence of randomness, a non-magnetic disordered insulating phase emerges. Inside this disordered insulator phase, there is a crossover from a gapless Anderson-like insulator to a gapped Mott-like insulator.

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Tianxing Ma, Lufeng Zhang, Chia-Chen Chang, Hsiang-Hsuan Hung, Richard T. Scalettar. 2016-10-31. A correlated Anderson insulator on the honeycomb lattice. https://doi.org/10.1103/physrevlett.120.116601

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