The magnetic fields with the first- and second-order gradient are engineered in several mechanically controlled hybrid systems. The current-carrying nanowires with different geometries can induce a tunable magnetic field gradient because of their geometric symmetries, and therefore develop various couplings to nitrogen-vacancy (NV) centers. For instance, a straight nanowire can guarantee the Jaynes-Cummings (JC) spin-phonon interaction and may indicate a potential route towards the application on quantum measurement. Especially, two parallel straight nanowires can develop the coherent down-conversion spin-phonon interaction through a second-order gradient of the magnetic field, and it can induce a bundle emission of the antibunched phonon pairs via an entirely different magnetic mechanism. Maybe, this investigation is further believed to support NV's future applications in the area of quantum manipulation, quantum sensing, and precision measurement, etc.
Demonstration of Robust Chiral Edge Transport in Field-Induced Chern Insulator MnBi2Te4 Devices with Engineered Geometric Defects
International Center for Quantum Materials, School of Physics, Peking University（北京大学物理学院量子材料国际中心）；Beijing Key Laboratory of Quantum Devices, Peking University（北京大学北京量子器件重点实验室）；State Key Laboratory of Quantum Functional Materials, and ShanghaiTech Laboratory for Topological Physics, School of Physical Science and Technology, ShanghaiTech University（上海科技大学物理科学与技术学院量子功能材料国家重点实验室及拓扑物理上海科技大学实验室）；National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Advanced Manufacturing Engineering, Nanjing University（南京大学先进微结构协同创新中心固体微观结构国家重点实验室先进制造工程学院）；National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University（南京大学固体微观结构国家重点实验室先进微结构协同创新中心物理学院）；Atom Manufacturing Institute（原子制造研究所）；Hefei National Laboratory（合肥国家实验室）；Collaborative Innovation Center of Quantum Matter（量子物质协同创新中心）
Quantum geometric scattering of a Dirac particle by a Berry curvature domain wall
1 Laboratoire de Physique de la Mati\`ere Condens\'ee, Facult\'e des Sciences de Tunis, Universit\'e Tunis El Manar, Campus Universitaire 1060 Tunis, Tunisia 2 Universit\'e Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay Cedex, France
Magnetic field sensitivity and decoherence spectroscopy of an ensemble of narrow-linewidth nitrogen-vacancy centers close to a diamond surface
我们进行脉冲光学检测电子自旋共振测量的直流磁场灵敏度和电子自旋相干时间T_2的近表面，高密度氮空位（NV）中心设计有一个狭窄的磁共振线宽的合奏。将脉冲光谱与动态核极化相结合，获得了35 nT Hz^{-0.5}的光子散粒噪声限制的直流磁灵敏度。我们发现，T_2是由瞬时扩散控制，使退相干光谱的残留氮杂质自旋在金刚石晶格和定量测定其密度。所展示的高直流磁灵敏度和退相干光谱有望拓宽二维磁成像的应用范围。
Experimental test of fluctuation relations for driven open quantum systems with an NV center
由于区分功和热在概念上和操作上的困难，受驱动的开放量子系统的量子涨落关系的实验验证目前是一个挑战。金刚石中的氮空位中心最近被提议作为一个受控的测试床，以研究在没有工作的情况下，在工程耗散通道存在下的波动关系[Hernán-Gómez等人，Phys. Rev. Research 2，023327（2020）]。在这里，我们将这些研究扩展到探索驱动耗散场景中量子涨落关系的有效性，其中自旋由于热梯度而与周围环境交换能量，并与外部工作源交换能量。我们实验证明的有效性的量子涨落关系中存在的循环驱动在两种情况下，当自旋交换能量与一个有效的无限温度的水库，当总工作消失在频闪时间-虽然提供给NV中心的功率是非零的。我们的结果代表了第一个实验研究的量子涨落关系的驱动开放量子系统。
