Effect of uncorrelated on-site scalar potential and mass disorder on transport of two-dimensional Dirac fermions

In this paper, we have studied the transport properties of a massive Dirac fermion in the simultaneous presence of scalar potential disorder 1V and mass disorder 1M. Our numerical calculations use the real space tight-binding model on a lattice with on-site uncorrelated disorder developed by Tworzydło et at. We study three different average masses, M¯ , which is interpreted as the band gap. In all three cases, despite the band gap, we identify that a critical 1V ∗(M¯ ) exists above which the system can no longer be an insulator for any 1M. The results support the idea of band gap suppression by onsite Coulomb potential. For 1V < 1V ∗, the system can be in an insulating or metallic phase, depending on the 1M value. As 1M increases, the system exhibits an insulator-to-metal transition at a critical value 1M∗(M¯ , 1V ). We have numerically estimated the critical values, 1V ∗, and 1M∗, for different M¯ values. Our work demonstrates the interdependent way different types of disorders can affect the phases accessible to a massive Dirac fermion system.

Recommended citation: Duha, Arman, and Mario F. Borunda. "Effect of uncorrelated on-site scalar potential and mass disorder on transport of two-dimensional Dirac fermions." Physical Review B 110.9 (2024): 094205.
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