Controlled Quantum Operations of a Semiconductor Three-Qubit System
Hai-Ou Li, Gang Cao, Guodong Yu, Ming Xiao, Guang‐Can Guo, Hong-Wen Jiang, Guo‐Ping Guo · Physical Review Applied · 2018
In semiconductor-based quantum computing, gate operations beyond the two-qubit limit are important, but have remained extremely challenging. The authors realize gate-voltage control of interqubit couplings in a specially designed three-qubit quantum-dot device. They exercise coherent control of both amplitude and phase of a target qubit using the prepared states of two control qubits, and demonstrate the basic functionalities of the universal Toffoli gate. This initial effort to achieve controlled three-qubit operations provides useful insight for research on multiqubit systems in semiconductor devices.