1201.5679 (A. T. Hatke et al.)

Giant negative magnetoresistance in high-mobility 2D electron systems    [PDF]

A. T. Hatke, M. A. Zudov, J. L. Reno, L. N. Pfeiffer, K. W. West

We report on a giant negative magnetoresistance in very high mobility
GaAs/AlGaAs heterostructures and quantum wells. The effect is the strongest at
$B \simeq 1$ kG, where the magnetoresistivity develops a minimum emerging at $T
\lesssim 2$ K. Unlike the zero-field resistivity which saturates at $T \simeq 2
$ K, the resistivity at this minimum continues to drop at an accelerated rate
to much lower temperatures and becomes several times smaller than the
zero-field resistivity. Unexpectedly, we also find that the effect is destroyed
not only by increasing temperature but also by modest in-plane magnetic fields.
The analysis shows that giant negative magnetoresistance cannot be explained by
existing theories considering interaction-induced or disorder-induced
corrections.

View original: http://arxiv.org/abs/1201.5679