Dr. Rafi de Picciotto, Bell-Labs, Lucent Technologies, Murray Hill, NJ
"The 0.7 structure in Cleaved Edge Overgrowth Wires"
Abstract: The so-called "0.7 structure" is a conductance anomaly found in ballistic one-dimensional wires and constrictions. This phenomenon remains poorly understood despite multitude research efforts. Several different theoretical models have been put forward, yet no single model fully accounts for the observed behaviors. In this talk I will describe our studies of the 0.7 anomaly in clean and long one-dimensional wires of highly controlled geometry, afforded by Molecular Beam Epitaxy growth onto the cleaved edge of a high-quality AlGaAs heterostructure. These unique Cleaved Edge Overgrowth wires allow for a quantitative comparison between the observed behaviors and various models.