Electron spins in semiconductor quantum dots are a promising platform for qubits. An essential step toward quantum error correction with spin qubits requires the ability to read out states and identify errors in the two-spin logical basis in a fast and high-fidelity way. Here we propose a scheme for spin singlet-triplet readout in a double quantum dot, with a superconducting resonator serving as the detector. Making use of a spin driving pulse sequence, this procedure can read out the spin states with a fidelity of $99.9\%$ in a time 100 ns. Interestingly, this method makes use of the spin driving pulse to adjust the resonator signal field, leading to significant improvement of the spin readout. In addition, this method can be directly applied to multiplexed readout of qubits and repeated readout to identify logical errors. These results pave the way for the implementation of quantum error correction and scalable quantum processor with spin qubits.

中文翻译：

---

使用谐振器和定制脉冲在单重态-三重态基础上快速高保真自旋读出

半导体量子点中的电子自旋是量子位的有前途的平台。使用自旋量子位进行量子纠错的重要步骤需要能够以快速和高保真方式读出状态并识别双自旋逻辑基础中的错误。在这里，我们提出了一种双量子点中自旋单重态-三重态读出的方案，其中超导谐振器用作检测器。利用自旋驱动脉冲序列，该程序可以读出自旋状态的保真度$99.9\%$在 100 ns 的时间内。有趣的是，这种方法利用自旋驱动脉冲来调整谐振器信号场，从而显着改善自旋读数。此外，该方法可以直接应用于量子比特的复用读出和重复读出以识别逻辑错误。这些结果为使用自旋量子位实现量子纠错和可扩展量子处理器铺平了道路。