Simulation Study of Charge Modulation in Coupled Quantum Dots in Silicon

Abstract

We have calculated electron states in a lithographically defined Si double quantum dot (DQD) device. Electrons are confined near the upper interface in the silicon-on-insulator (SOI) layer by top gate and side gate voltages. Surface charge density, N S, at 4 K in DQDs is evaluated using experimental data of the gate voltage dependence of N S in a metal–oxide–semiconductor (MOS) transistor at 100 and 4 K. With optimum side gate biases, electrons are confined in QDs and coupling between QDs is controlled in a few-electron regime. We have also proposed that a charge sensor is required to read out the few-electron regime because no current flows in the DQD device.

Dual Function of Single Electron Transistor Coupled with Double Quantum Dot: Gating and Charge Sensing

“…Si DQD, single QD (SQD), and gates are fabricated by electron beam lithography, dry etching, and thermal oxidation. 9,11,20) Constricted regions between QDs and reservoirs work as potential barriers for the DQD and SQD. The back gate (BG) is used to induce two-dimensional electron gas at the lower Si/SiO 2 interface in the silicon-oninsulator (SOI) layer, which acts as a gate of a metal-oxidesemiconductor field-effect transistor (MOSFET) structure.…”