Anisotropic, two-dimensional, disordered Wigner solid

Abstract

The interplay between the Fermi sea anisotropy, electron-electron interaction, and localization phenomena can give rise to exotic many-body phases. An exciting example is an anisotropic two-dimensional (2D) Wigner solid (WS), where electrons form an ordered array with an anisotropic lattice structure. Such a state has eluded experiments up to now as its realization is extremely demanding: First, a WS entails very low densities where the Coulomb interaction dominates over the kinetic (Fermi) energy. Attaining such low densities while keeping the disorder low is very challenging. Second, the low-density requirement has to be fulfilled in a material that hosts an anisotropic Fermi sea. Here, we report transport measurements in a clean (low-disorder) 2D electron system with anisotropic effective mass and Fermi sea. The data reveal that at extremely low electron densities, when the r_s parameter, the ratio of the Coulomb to the Fermi energy, exceeds 38, the current-voltage characteristics become strongly nonlinear at small dc biases. Several key features of the nonlinear characteristics, including their anisotropic voltage thresholds, are consistent with the formation of a disordered, anisotropic WS pinned by the ubiquitous disorder potential.

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Cited by in corpus (21)

• Theory of Generalized Landau Levels and Implication for non-Abelian States
• Ground state phases of the two-dimension electron gas with a unified variational approach
• Observation of an electronic microemulsion phase emerging from a quantum crystal-to-liquid transition
• Nonlinear Dynamics, Avalanches and Noise for Driven Wigner Crystals
• 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
• Nematic metal in a multi-valley electron gas: Variational Monte Carlo analysis and application to AlAs
• Signatures of correlated defects in an ultra-clean Wigner crystal in the extreme quantum limit
• Collective depinning and sliding of a quantum Wigner solid in a 2D electron system
• Collective Dynamics and Defect Generation for Wigner Crystal Ratchets
• Noise and Thermal Depinning of Wigner Crystals
• Ferromagnetic semimetal and charge-density wave phases of interacting electrons in a honeycomb moiré potential
• Melting, Reentrant Ordering and Peak Effect for Wigner Crystals with Quenched and Thermal Disorder
• Thermal melting of a quantum electron solid in the presence of strong disorder: Anderson versus Wigner
• Critical gate distance for Wigner crystallization in the two-dimensional electron gas
• Stabilization of a two-dimensional quantum electron solid in perpendicular magnetic fields
• Developing fractional quantum Hall states at $\nu$ = $\frac{1}{7}$ and $\frac{2}{11}$ in the presence of significant Landau level mixing
• An unusual first order phase transition in a 2D superconductor
• Inequivalence of the low-density insulating state and quantum Hall insulating states in a strongly correlated two-dimensional electron system
• Magnetic Field Effects and Transverse Ratchets in Charge Lattices Coupled to Asymmetric Substrates
• Quantum Wigner solid in two-dimensional electron systems in semiconductors