Anomalous nematic states in half-filled high Landau levels*

It is well established that the ground states of a two-dimensional electron gas with half-filled high (N ≥ 2) Landau levels are compressible charge-ordered states, known as quantum Hall stripe (QHS) phases. The generic features of QHSs are a maximum (minimum) in a longitudinal resistance R_xx (R_yy) and a non-quantized Hall resistance R_H. This talk will report on emergent minima (maxima) in R_xx (R_yy) and plateau-like features in R_H in half-filled N ≥ 3 Landau levels. Remarkably, these unexpected features emerge at temperatures considerably lower than the onset temperature of QHSs, suggestive of a new ground state.