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Orbital Magnetization Measurement of the Quantum Hall to Insulator Transition

D. R. Faulhaber·H. W. Jiang
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Abstract

We present a magnetization measurement probing the transition from a quantum Hall to insulating (QH-I) state for a two-dimensional electron gas in a disordered GaAs/AlGaAs heterostructure. Using a highly sensitive DC torque magnetometer, we discover an abrupt change in the orbital magnetization precisely at the critical point for the QH-I transition. Since this transition is predicted to be a second order quantum phase transition, a thermodynamic signature in magnetization is totally unexpected. The observed feature is reminiscent of the well-known de Haas-van Alphen oscillations arising from discontinuous jumps of the chemical potential as Landau Levels are successively populated.

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D. R. Faulhaber, H. W. Jiang. 2003-09-03. Orbital Magnetization Measurement of the Quantum Hall to Insulator Transition. https://arxiv.org/abs/cond-mat/0309087

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