Fast high-fidelity parity measurement of spin qubits in quantum dots using modulated pulses

Spin qubits in semiconductor quantum dots are a promising candidate for scalable quantum computation. A key step in quantum error correction with spin qubits is the capability to perform high-fidelity parity measurement much faster than the coherence time and to generate entanglement deterministically. Here we propose a parity measurement scheme for two spin qubits by modulated pulses, using a superconducting resonator as a detector. We show that the distinction between spin-parity states can be achieved with a high fidelity within a short measurement time. The combination of parity measurement and feedback control allows the deterministic preparation of various spin entangled states. In addition, the method can be directly applied to parity measurements and surface codes of multiple spin qubits. These results pave the way for fault-tolerant quantum computation with spin qubits.

Automated summary

In this paper, a strategy for measuring the parity of two spin qubits using modulated pulses and a superconducting resonator as a detector is proposed. It is found that the distinction between spin-parity states can be achieved with high fidelity within a short measurement time, enabling the deterministic preparation of various spin entangled states. The method can also be applied to parity measurements and surface codes of multiple spin qubits. These results pave the way for fault-tolerant quantum computation with spin qubits.