Coherent electron transport in silicon quantum dots

Xinyu Zhao, Xuedong Hu

Published 2018-03-02Version 1

In this paper, we study the electron transport in silicon double quantum dots. First, in the valley-orbital dynamics, we propose a practical scheme to detect the valley phase difference between two dots by utilizing the Landau-Zener-St\"{u}ckelburg interference. An equation is derived to compute the phase difference from the data measured in the interference pattern. We also discuss the feasibility of implementing the scheme with current experimental technologies. Second, taking spin degree of freedom into consideration, we show the inhomogeneous magnetic field and the spin orbit coupling can cause considerable spin flip errors. We analyze how does the valley splitting affect the formation of spin-valley anti-crossings. At last, we discuss a natural decoherence mechanism in silicon quantum dots caused by the mixing between spin and valley states. We show an example that the classical information (spin population) is faithfully transported but the quantum information (coherence) is lost.