Nonequilibrium phenomena in bilayer electron systems

Magnetoresistance of bilayer electron systems with relatively large inter-layer separation shows hysteresis when the filling factor of one of the layers is close to integer values. This hysteresis indicates the absence of equilibrium between the layers [1,2]. In the present work, we performed magnetocapacitance measurements to study the system when both layers are in the quantum Hall effect regime. Results show that the magnetic field sweep drives the system out of equilibrium even when the densities of individual layers are equal, leading to magnetocapacitance hysteresis. This indicates that magnetic field sweep most likely breaks not only inter- but also intra-layer equilibrium.

References:

1. Kellogg et al, Phys. Rev. Lett. 88, 126804 (2002).

2. Zhu et al, Phys. Rev. B 61, R13361 (2000).