Electrical control of tunnel characteristics is demonstrated in a vertically coupled quantum point contact (VCQPC) formed in a bilayer two-dimensional electron system. In this VCQPC, the geometry of potential is controlled by voltages applied to split-gates, a midline-gate, and a back-gate. In particular, the vertical alignment of upper and lower quantum point contact (QPCs) can be electrically tuned. When the two QPCs are misaligned, coupling appears between all one-dimensional (1D) subbands arising from the two QPCs. The coupling strength between the lowest 1D subbands becomes smaller with increasing misalignment because of the smaller overlap of the wavefunctions.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)