Thermal melting of a quantum electron solid in the presence of strong disorder: Anderson versus Wigner

Abstract

We consider temperature-induced melting of a Wigner solid in one dimensional (1D) and two dimensional (2D) lattices of electrons interacting via the long-range Coulomb interaction in the presence of strong disorder arising from charged impurities in the system. The system simulates semiconductor-based 2D electron layers where Wigner crystallization is often claimed to be observed experimentally. Using exact diagonalization and utilizing the inverse participation ratio as well as conductance to distinguish between the localized insulating solid phase and the extended metallic liquid phase, we find that the effective melting temperature may be strongly enhanced by disorder since the disordered crystal typically could be in a localized glassy state incorporating the combined nonperturbative physics of both Anderson localization and Wigner crystallization. This disorder-induced enhancement of the melting temperature may explain why experiments often manage to observe insulating disorder-pinned Wigner solids in spite of the experimental temperature being decisively far above the theoretical melting temperature of the pristine Wigner crystal phase in many cases.

5+3 pages, 3+5 figures

References in corpus (7)

• Observation of Wigner crystal of electrons in a monolayer semiconductor
• Phase Diagram of the Low-Density Two-Dimensional Homogeneous Electron Gas
• Competing correlated states around the zero field Wigner crystallization transition of electrons in two-dimensions
• Observation of Spontaneous Ferromagnetism in a Two-Dimensional Electron System
• Transport in two-dimensional modulation doped semiconductor structures
• Anisotropic, two-dimensional, disordered Wigner solid
• Scattering Mechanisms in a High Mobility Low Density Carbon-Doped (100) GaAs Two-Dimensional Hole System

Cited by in corpus (5)

• Thermal crossover from a Chern insulator to a fractional Chern insulator in pentalayer graphene
• Electronic transport, metal-insulator transition, and Wigner crystallization in transition metal dichalcogenide monolayers
• Density-tuned effective metal-insulator transitions in 2D semiconductor layers: Anderson localization or Wigner crystallization
• Short-range interactions are irrelevant at the quasiperiodic-driven Luttinger Liquid to Anderson Glass transition
• Stability of Wigner crystals and Mott insulators in twisted moiré structures