A Disguised Switch for Two-Qubit Gates of a Hybrid Quantum Processing Unit

Abstract

The key mechanism which enables two-qubit operations of a hybrid quantum processing unit for hybrid quantum computing is demonstrated. A scheme which realizes a disguised switch for two-qubit gating is proposed, combining external magnetic field control, quantum dot sample tuning, and assisted laser control. Our methods overcome the limitation of asynchrony between single-qubit operations of respective solid-state qubits and improve the efficiency of single-qubit gating.

Appendix: Parameters of the Effective Hamiltonian

The parameters of the effective Hamiltonian in (8) and (9) are given as below

$$\begin{array}{@{}rcl@{}} \lambda_{1}&=&\frac{g\Omega^{*}}{4}\left(\frac{1}{\Delta+\delta-\sqrt{2}\nu}+\frac{1}{\Delta}\right),\\ \lambda_{2}&=&\frac{g\Omega^{*}}{4}\left(\frac{1}{\Delta+\delta+\sqrt{2}\nu}+\frac{1}{\Delta}\right),\\ \lambda_{0}&=&\frac{\sqrt{2}g\Omega^{*}}{4}\left(\frac{1}{\Delta+\delta}+\frac{1}{\Delta}\right),\\ \kappa_{1}&=&\frac{\left|g\right|^{2}}{8}\left(\frac{1}{\Delta+\delta-\sqrt{2}\nu}+\frac{1}{\Delta_{1}+\delta+\Delta+\sqrt{2}\nu}\right),\\ \kappa_{2}&=&\frac{\sqrt{2}\left|g\right|^{2}}{8}\left(\frac{1}{\Delta+\delta+\sqrt{2}\nu}+\frac{1}{\Delta_{1}+\delta+\Delta}\right),\\ \kappa_{0}&=&\frac{\sqrt{2}\left|g\right|^{2}}{8}\left(\frac{1}{\Delta+\delta-\sqrt{2}\nu}+\frac{1}{\Delta_{1}+\delta+\Delta}\right),\\ \varepsilon_{1}&=&\frac{|g|^{2}}{4(\Delta+\delta-\sqrt{2}\nu)},\\ \varepsilon_{2}&=&\frac{|g|^{2}}{4(\Delta+\delta+\sqrt{2}\nu)},\\ \varepsilon_{0}&=&\frac{|g|^{2}}{2(\Delta+\delta)},\\ \epsilon_{+}&=&\frac{|\Omega|^{2}}{2\Delta}, \end{array} $$