Induced currents in the quantum Hall regime: Energy storage, persistence, andI-Vcharacteristics

Abstract

Induced currents associated with the quantum Hall effect are studied in the temperature range $39\phantom{\rule{0.28em}{0ex}}\mathrm{mK}$ to $1.6\phantom{\rule{0.28em}{0ex}}\mathrm{K}$, and at Landau-level filling factors $\ensuremath{\nu}=1,2,3,4$, and 6, using torsion-balance magnetometry. A quantitative link is demonstrated between (nonlinear induced current) vs (inducing electromotive force) curves, and the subexponential decay of the induced current in a static magnetic field. The energy storage in the induced currents is reexamined with the conclusion that the predominant mechanism for storage is inductive, through the mutual inductance between the sample and the magnet, not capacitive as previous reports have assumed. The temperature dependencies of the currents are consistent with previous models, except for a low-temperature saturation at filling factors $\ensuremath{\nu}=1$ and $\ensuremath{\nu}=2$, which we attribute to electron heating.