Anomalous hysteretic behavior induced by Landau level pinning

We studied two-dimensional electron systems confined in asymmetric wide GaAs quantum wells at high magnetic field with capacitance measurement method. Because of the interlayer Coulomb interaction, Landau levels from different subbands will be pinned together when they cross at Fermi energy, leading to a charge instability. Our capacitance measurement reveals hysteretic behavior and two split minima around q/3 states related to this phenomenon.