伊朗谢里夫理工大学David G. Cory团队研究了稳健的微观-宏观纠缠态。相关论文于2025年4月14日发表在《物理评论A》杂志上。

量子比特和介观系统宏观上不同的态之间的二分纠缠态，称为微观-宏观纠缠态，是量子信息处理的新兴资源。在实验室中产生这种状态的一个主要挑战是它们对环境噪声的脆弱性。研究组通过识别哪些因素在鲁棒性中起作用并量化其影响，详细分析了单粒子噪声的这种脆弱性。微观-宏观纠缠态的宏观性与其二分纠缠对环境噪声的鲁棒性之间存在权衡。

研究组确定对称微观-宏观纠缠态是对单粒子噪声最稳健的状态。他们表明，这种态的二分纠缠对单粒子噪声的鲁棒性随着宏观二阶的降低而降低，这表明二分纠缠态既鲁棒又宏观。该结果是朝着在大尺度上保持量子特性和实验实现微观-宏观纠缠自旋态及其用于连接分离的量子比特迈出了一步。此外，它深化了人们对量子到经典跃迁的理解。

附：英文原文

Title: Robust micro-macro entangled states

Author: Maryam Sadat Mirkamali, David G. Cory

Issue&Volume: 2025/04/14

Abstract: Bipartite entangled states between a qubit and macroscopically distinct states of a mesoscopic system, known as micro-macro entangled states, are emerging resources for quantum information processing. One main challenge in generating such states in the laboratory is their fragility to environmental noise. We analyze this fragility in detail for single-particle noise by identifying what factors play a role in the robustness and quantifying their effect. There is a trade-off between the macroscopicity of a micro-macro entangled state and the robustness of its bipartite entanglement to environmental noise. We identify symmetric micro-macro entangled states as the most robust states to single-particle noise. We show that the robustness of bipartite entanglement of such states to single-particle noise decreases as the second order of macroscopicity, which identifies a regime where the bipartite entangled state is both robust and macroscopic. Our result is a step towards retaining quantum characteristics on large scales and experimental realization of micro-macro entangled spin states and their use for connecting separated qubits. Moreover, it advances our understanding of quantum to classical transition.

DOI: 10.1103/PhysRevA.111.042206

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.042206