Capacitive Response of Wigner Crystals at the Quantum Hall Plateau

Abstract

In this report, we study ultra-high-mobility two-dimensional (2D) electron/hole systems with high precision capacitance measurement. We find that the capacitance charge appears only at the fringe of the gate at high magnetic field when the 2D conductivity decreases significantly. At integer quantum Hall effects, the capacitance vanishes and forms a plateau at high temperatures $T\gtrsim 300$ mK, which surprisingly, disappears at $T\lesssim 100$ mK. This anomalous behavior is likely a manifestation that the dilute particles/vacancies in the top-most Landau level form Wigner crystal, which has finite compressibility and can host polarization current.

References in corpus (5)

• Microwave Resonance of 2D Wigner Crystal around integer Landau fillings
• Probing the Melting of a Two-dimensional Quantum Wigner Crystal via its Screening Efficiency
• Determination of $g$-factor in InAs two-dimensional electron system by capacitance spectroscopy
• Magnetotransport patterns of collective localization near $\nu =1$ in a high-mobility two-dimensional electron gas
• High Precision, Low Excitation Capactiance Measurement Methods from 10 mK- to Room-Temperature

Cited by in corpus (5)

• Dynamic Response of Wigner Crystals
• Interaction between Surface Acoustic Wave and Quantum Hall Effects
• Thermal Activation Signatures of the Anderson Insulator and the Wigner Solid forming near $\nu =1$
• Density Dependence of the Phases of the $\nu =1$ Integer Quantum Hall Plateau in Low Disorder Electron Gases
• Anomalous acousto-current within the quantum Hall plateaus