1204.5712 (C. Dillard et al.)

Breakdown of the integer and fractional quantum Hall states in a quantum
point contact    [PDF]

C. Dillard, X. Lin, M. A. Kastner, L. N. Pfeiffer, K. W. West

The integer and fractional quantum Hall states are known to break down at high dc bias, exhibiting deviation from the ideal incompressible behavior. We measure breakdown of the \nu = 2, 3, 4, 5 integer and the \nu = 4/3 and 5/3 fractional states in a quantum point contact (QPC) of lithographic width ~600 nm. Dependence of the critical current on magnetic field, QPC gate voltage, and QPC width are presented. Of particular interest, the critical current of the 4/3 and 5/3 fractional states shows the opposite dependence on QPC width compared to the integer states. This previously unobserved result is not explained by current theories of breakdown.

View original: http://arxiv.org/abs/1204.5712