Gated-charge force microscopy for imaging a surface-acoustic-wave-induced charge in a depleted one-dimensional channel

摘要

Gated-charge force microscopy (GCFM) generates images of subsurface induced charge with single-electron charge resolution and zero sensitivity to background charge, for the noninvasive study of confined quantum electronic systems. By gating the radio-frequency signal applied to transducers, which generate surface-acoustic waves (SAWs), we use GCFM to generate images of a GaAs depleted one-dimensional channel and provide insight to SAW-induced transport. Unexpected SAW-induced subsurface charge was imaged at points of high potential gradient. This suggests that electrons depopulating a SAW minimum due to a high potential gradient rapidly lose energy and interact with following SAW minima.