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Valley Phase and Voltage Control of Coherent Manipulation in Si Quantum Dots

Published

Author(s)

Neil M. Zimmerman, Peihao Huang, Dimitrie Culcer

Abstract

With any roughness at the interface of an indirect-bandgap semiconducting dot, the phase of the valley-orbit coupling can take on a random value. This random value, in double quantum dots, causes a large change in the exchange splitting. We demonstrate a simple analytical method to calculate the phase, and thus the exchange splitting and singlet−triplet qubit frequency, for an arbitrary interface. We then show that, with lateral control of the position of a quantum dot using a gate voltage, the valley−orbit phase can be controlled over a wide range, so that variations in the exchange splitting can be controlled for individual devices. Finally, we suggest experiments to measure the valley phase and the concomitant gate voltage control.
Citation
Nano Letters

Keywords

Si valley, phase, voltage control

Citation

Zimmerman, N. , Huang, P. and Culcer, D. (2017), Valley Phase and Voltage Control of Coherent Manipulation in Si Quantum Dots, Nano Letters, [online], https://doi.org/10.1021/acs.nanolett.7b01677 (Accessed August 10, 2022)
Created June 28, 2017, Updated November 10, 2018