Robust deterministic quantum computation of quantum-dot spins inside microcavities based on parity-check building blocks

Abstract

Parity-check building blocks are useful in quantum algorithms, quantum communications, and quantum computing, and such devices may be helpful in implementing robust universal quantum gates. We propose a scheme to construct a robust deterministic controlled-not gate on static electron-spin qubits with parity-check building blocks, assisted by double-sided-cavity quantum systems. Our device is robust against the polarization-flip errors, and it can work in both the weak coupling and strong coupling regimes, but high fidelity is achieved only when the ratio of the side leakage to the cavity loss is low. Our gate is heralded by the polarization of the single-photon medium. Finally, we assess the feasibility of this device and show it can be implemented with current technology.