近日，意大利佛罗伦萨大学Giulia Del Pace团队研究了强相互作用费米气体中的夏皮罗阶跃。该研究于2025年12月11日发表在《科学》杂志上。

受驱动的多体系统表现出多样化且复杂的动力学行为。

研究组报告了在强相互作用的超冷原子费米超流体之间的周期性驱动约瑟夫森结中观察到的夏皮罗阶跃。在电流-电位特性中观测到的量化平台的高度和宽度反映了外部驱动频率和结的非线性响应。电流-相位关系的直接测量表明，夏皮罗阶跃是如何由两个储层的相对相位和外部驱动之间的同步中产生的。以涡旋-反涡旋对的形式检测周期性相位滑移过程，进一步支持了这种机制。该结果得到了电路模型和数值模拟的证实。该工作为研究外部驱动下量子多体系统的涌现非平衡动力学开辟了前景。

附：英文原文

Title: Shapiro steps in strongly-interacting Fermi gases

Author: Giulia Del Pace, Diego Hernández-Rajkov, Vijay Pal Singh, Nicola Grani, Marcia Frómeta Fernández, Giulio Nesti, Jorge Amin Seman, Massimo Inguscio, Luigi Amico, Giacomo Roati

Issue&Volume: 2025-12-11

Abstract: Driven many-body systems exhibit diverse and complex dynamical behaviors. Here, we report the observation of Shapiro steps in periodically driven Josephson junctions between strongly interacting Fermi superfluids of ultracold atoms. The height and the width of the observed quantized plateaus in the current-potential characteristics mirror the external drive frequency and the junction nonlinear response. Direct measurements of the current-phase relationship showcase how Shapiro steps arise from the synchronization between the relative phase of the two reservoirs and the external drive. Such a mechanism is further supported by the detection of periodic phase-slippage processes, in the form of vortex-antivortex pairs. Our results are corroborated by a circuital model and numerical simulations. Our work may open prospects for studying emergent nonequilibrium dynamics in quantum many-body systems under external drives.

DOI: ads8885

Source: https://www.science.org/doi/10.1126/science.ads8885