近日，法国巴黎萨克雷大学Emmanuel Flurin团队研究了相干度超过秒的单个固态核自旋量子位。2025年10月22日，《自然—物理学》杂志发表了这一成果。
相干控制和读出量子位的能力是任何量子处理器的关键要求。固态系统中的单个核自旋一直应用长寿命量子比特，具有控制和读出功能，并使用单个电子自旋辅助量子比特，这些量子比特可以电或光学处理。
研究组提出了一个量子信息处理平台，由183W的核自旋量子比特组成，该量子比特靠近CaWO4晶体中的Er3+杂质，并与超导谐振器耦合。研究组分析了两个核自旋量子比特，其退相干时间T2*分别为0.8(2)秒和1.2(3)秒，而T2相干时间分别为3.4(4)秒和4.4(6)秒。
核自旋态影响Er3+电子辅助自旋量子位元重复激发后发射的光子数，使单微波光子探测器的量子非拆除读出成为可能。利用受激拉曼驱动耦合电子-核-自旋系统，研究组在几毫秒的时间尺度上实现了全微波的一个和两个量子比特门，并制备了退相干保护的贝尔态。该研究结果将这个平台定位为量子处理核自旋应用的潜在途径。
附：英文原文
Title: Individual solid-state nuclear spin qubits with coherence exceeding seconds
Author: OSullivan, James, Travesedo, Jaime, Pallegoix, Louis, Huang, Zhiyuan W., Hogan, Patrick, May, Alexandre S., Yavkin, Boris, Lin, Sen, Liu, Ren-Bao, Chaneliere, Thierry, Bertaina, Sylvain, Goldner, Philippe, Estve, Daniel, Vion, Denis, Abgrall, Patrick, Bertet, Patrice, Flurin, Emmanuel
Issue&Volume: 2025-10-22
Abstract: The ability to coherently control and read out qubits is a crucial requirement for any quantum processor. Individual nuclear spins in solid-state systems have been used as long-lived qubits with control and readout performed using individual electron spin ancilla qubits that can be addressed either electrically or optically. Here we present a platform for quantum information processing, consisting of 183W nuclear spin qubits adjacent to an Er3+ impurity in a CaWO4 crystal coupled to a superconducting resonator. We study two nuclear spin qubits with ({T}_{2}^{* }) of 0.8(2)s and 1.2(3)s, and T2 of 3.4(4)s and 4.4(6)s, respectively. The nuclear spin state influences the number of photons emitted after repeated excitation of the Er3+ electron ancilla spin qubit, enabling quantum non-demolition readout using a single microwave photon detector. Using stimulated Raman driving on the coupled electron–nuclear-spin system, we implement all-microwave one- and two-qubit gates on a timescale of a few milliseconds, and prepare a decoherence-protected Bell state. Our results position this platform as a potential route towards quantum processing using nuclear spins.
DOI: 10.1038/s41567-025-03049-7
Source: https://www.nature.com/articles/s41567-025-03049-7