Conductance anomaly in a GaAs/Ga0.77Al0.23As heterojunction

We have observed a sharp drop by several percent in the conductance of a GaAs/Ga0.77Al0.23As heterojunction with decreasing temperature near 4 K. The width of the transition is approximately 0.5 K. The transition has a strong magnetic field dependence which is both anisotropic and hysteretic. Below the transition the dc conductivity is strongly non-Ohmic. We attribute this striking behavior to the formation of a mixed density wave, involving both charge- and spin-density-wave characteristics. © 1986 The American Physical Society.