Evidence for an Anisotropic State of Two-Dimensional Electrons in High Landau Levels
نویسندگان
چکیده
Magnetotransport experiments on high mobility two-dimensional electron gases in GaAsyAlGaAs heterostructures have revealed striking anomalies near half filling of several spin-resolved, yet highly excited, Landau levels. These anomalies include strong anisotropies and nonlinearities of the longitudinal resistivity rxx which commence only below about 150 mK. These phenomena are not seen in the ground state or first excited Landau level but begin abruptly in the third level. Although their origin remains unclear, we speculate that they reflect the spontaneous development of a generic anisotropic many-electron state. [S0031-9007(98)08178-2]
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Recent magneto-transport experiments on high mobility two-dimensional electron systems have provided strong evidence that a new class of collective electronic states exists at high Landau level occupancy. Among the phenomena observed are strongly anisotropic resistances near half-®lling and curious re-entrant integer quantum Hall states in the ̄anks of high Landau levels. These results have bee...
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