RF detection of split-gate modes in Si-MOS quantum dots

Abstract

Abstract Radio frequency (RF) reflectometry is an effective and sensitive technique for detecting charge signal in semiconductor quantum dots, and its measurement bandwidth can reach the MHz level. However, in accumulation mode devices, the presence of parasitic capacitance makes RF reflectometry more difficult. The universal approach is relocating the ion implantation region approximately 10 μm from the center of the single-electron transistor (SET) and optimizing the design of the accumulation gates. But, this method puts forward more stringent requirements for micro-nano fabrication processing. Here, we propose a split-gate structure that enables RF reflectometry when the ion-implanted region and the ohmic contact are farther from the SET center. In Si-MOS devices, we employ a split-gate structure to achieve RF detection, with the ion-implanted region located 150 μm away from the center of the SET. Within an integration time of 140 nanoseconds, we achieved a readout fidelity exceeding 99.8% and a detection bandwidth of over 2 MHz. This is an alternative solution for micro-nano fabrication processing that cannot achieve ion implantation areas closer to the center of the chip, and is applicable to various silicon-based semiconductor systems.