Zhang Pengfei, Gao Yu, Xu Xiansong, Wang Ning, Dong Hang, Guo Chu, Deng Jinfeng, Zhang Xu, Chen Jiachen, Xu Shibo, Wang Ke, Wu Yaozu, Zhang Chuanyu, Jin Feitong, Zhu Xuhao, Zhang Aosai, Zou Yiren, Tan Ziqi, Cui Zhengyi, Zhu Zitian, Shen Fanhao, Li Tingting, Zhong Jiarun, Bao Zehang, Zhao Liangtian, Hao Jie, Li Hekang, Wang Zhen, Song Chao, Guo Qiujiang, Wang H, Poletti Dario
School of Physics, ZJU-Hangzhou Global Scientific and Technological Innovation Center, and Zhejiang Key Laboratory of Micro-nano Quantum Chips and Quantum Control, Zhejiang University, Hangzhou, China.
Science, Mathematics and Technology Cluster, Singapore University of Technology and Design, Singapore, Singapore.
Nat Commun. 2024 Nov 22;15(1):10115. doi: 10.1038/s41467-024-54332-9.
Non-equilibrium quantum transport is crucial to technological advances ranging from nanoelectronics to thermal management. In essence, it deals with the coherent transfer of energy and (quasi-)particles through quantum channels between thermodynamic baths. A complete understanding of quantum transport thus requires the ability to simulate and probe macroscopic and microscopic physics on equal footing. Using a superconducting quantum processor, we demonstrate the emergence of non-equilibrium steady quantum transport by emulating the baths with qubit ladders and realising steady particle currents between the baths. We experimentally show that the currents are independent of the microscopic details of bath initialisation, and their temporal fluctuations decrease rapidly with the size of the baths, emulating those predicted by thermodynamic baths. The above characteristics are experimental evidence of pure-state statistical mechanics and prethermalisation in non-equilibrium many-body quantum systems. Furthermore, by utilising precise controls and measurements with single-site resolution, we demonstrate the capability to tune steady currents by manipulating the macroscopic properties of the baths, including filling and spectral properties. Our investigation paves the way for a new generation of experimental exploration of non-equilibrium quantum transport in strongly correlated quantum matter.
非平衡量子输运对于从纳米电子学到热管理等一系列技术进步至关重要。本质上，它涉及能量和（准）粒子通过热力学库之间的量子通道进行的相干转移。因此，对量子输运的全面理解需要有能力在同等基础上模拟和探究宏观与微观物理。利用超导量子处理器，我们通过用量子比特梯模拟库并在库之间实现稳定的粒子流，展示了非平衡稳态量子输运的出现。我们通过实验表明，电流与库初始化的微观细节无关，并且它们的时间涨落随着库的大小迅速减小，这与热力学库所预测的情况相似。上述特征是非平衡多体量子系统中纯态统计力学和预热化的实验证据。此外，通过利用具有单比特分辨率的精确控制和测量，我们展示了通过操纵库的宏观性质（包括填充和光谱性质）来调节稳定电流 的能力。我们的研究为在强关联量子物质中对非平衡量子输运进行新一代实验探索铺平了道路。
