Insulating State and Giant Nonlocal Response in an $\mathrm{In}\mathrm{As}/\mathrm{Ga}\mathrm{Sb}$ Quantum Well in the Quantum Hall Regime

Insulating State and Giant Nonlocal Response in an $In As / Ga Sb$ Quantum Well in the Quantum Hall Regime

Fabrizio Nichele, Atindra Nath Pal, Patrick Pietsch, Thomas Ihn, Klaus Ensslin, Christophe Charpentier, and Werner Wegscheider

Phys. Rev. Lett. 112, 036802 – Published 22 January 2014

Abstract

We present transport measurements performed in $InAs / GaSb$ double quantum wells. At the electron-hole crossover tuned by a gate voltage, a strong increase in the longitudinal resistivity is observed with increasing perpendicular magnetic field. Concomitantly with a local resistance exceeding the resistance quantum by an order of magnitude, we find a pronounced nonlocal resistance signal of almost similar magnitude. The coexistence of these two effects is reconciled in a model of counterpropagating and dissipative quantum Hall edge channels providing backscattering, shorted by a residual bulk conductivity.