Engineering Independent Electrostatic Control of Atomic-Scale (4 nm) Silicon Double Quantum Dots
详细信息 查看全文
- 作者：Bent Weber ; Suddhasatta Mahapatra ; Thomas F. Watson ; Michelle Y. Simmons
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：August 8, 2012
- 年：2012
- 卷：12
- 期：8
- 页码：4001-4006
- 全文大小：318K
- 年卷期：v.12,no.8(August 8, 2012)
- ISSN：1530-6992
文摘
Scalable quantum computing architectures with electronic spin qubits hosted by arrays of single phosphorus donors in silicon require local electric and magnetic field control of individual qubits separated by 10 nm. This daunting task not only requires atomic-scale accuracy of single P donor positioning to control interqubit exchange interaction but also demands precision alignment of control electrodes with careful device design at these small length scales to minimize cross capacitive coupling. Here we demonstrate independent electrostatic control of two Si:P quantum dots, each consisting of 15 P donors, in an optimized device design fabricated by scanning tunneling microscope (STM)-based lithography. Despite the atomic-scale dimensions of the quantum dots and control electrodes reducing overall capacitive coupling, the electrostatic behavior of the device shows an excellent match to results of a priori capacitance calculations. These calculations highlight the importance of the interdot angle in achieving independent control at these length-scales. This combination of predictive electrostatic modeling and the atomic-scale fabrication accuracy of STM-lithography, provides a powerful tool for scaling multidonor dots to the single donor limit.