Melting of Wigner crystal in high-mobility n-GaAs/AlGaAs heterostructures at filling factors 0.18 > nu > 0.125: Acoustic studies

Article

关键词: 2-DIMENSIONAL ELECTRON-SYSTEM;    CHARGE-DENSITY-WAVE;    INSULATING PHASE;    MAGNETIC-FIELD;    CONDUCTIVITY;    FREQUENCY;    ABSORPTION;    TRANSITION;    DYNAMICS;   

DOI  :  10.1103/PhysRevB.94.075420

来源: SCIE

【 摘 要 】

By using acoustic methods the complex high-frequency conductance of high-mobility n-GaAs/AlGaAs heterostructures was determined in magnetic fields 12-18 T. Based on the observed frequency and temperature dependences, we conclude that in the investigated magnetic field range and at sufficiently low temperatures, T less than or similar to 200 mK, the electron system forms a Wigner crystal deformed due to pinning by disorder. At some temperature, which depends on the electron filling factor, the temperature dependences of both components of the complex conductance get substantially changed. We have ascribed this rapid change of the conduction mechanism to melting of the Wigner crystal and study the dependence of the so-defined melting temperature on the electron filling factor.

【 授权许可】

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