德国HQS量子模拟公司Juha Leppkangas团队，报道了系统浴物理在基于门的量子计算机上的演示。相关论文于2025年2月13日发表于国际顶尖学术期刊《物理评论A》杂志上。

据悉，算法冷却可以以寻找多体量子系统的相关状态为主题。它基于执行非单一操作的量子电路，其在近期量子计算机上的实现可能具有挑战性。

在这项工作中，该团队开发了一种利用固有量子比特噪声，来实现非酉运算和算法冷却的方法。在他们的方法中，量子计算过程中的量子位衰变，以模拟辅助自旋浴的耗散为主题，辅助自旋浴使模拟系统冷却到基态。

研究人员在IBM-Q设备上测试了该算法，并证明了系统自旋在系统哈密顿量定义控制下的，铁磁和反铁磁有序弛豫。只要算法运行，排序是稳定的。该团队能够对多达三个系统自旋，及其辅助自旋的全局系统进行冷却和状态稳定。他们的工作为近期量子计算机上，多体量子系统的主题量子模拟铺平了道路。

附：英文原文

Title: Demonstration of system-bath physics on a gate-based quantum computer

Author: Pascal Stadler, Matteo Lodi, Andisheh Khedri, Rolando Reiner, Kirsten Bark, Nicolas Vogt, Michael Marthaler, Juha Leppkangas

Issue&Volume: 2025/02/13

Abstract: Algorithmic cooling can be used to find correlated states of many-body quantum systems. It is based on quantum circuits that perform nonunitary operations, whose implementation can be challenging on near-term quantum computers. In this work we develop a method that uses inherent qubit noise to implement nonunitary operations and algorithmic cooling. In our approach, qubit decay during quantum computation is used to simulate dissipation of auxiliary-spin bath, which cools down a simulated system towards its ground state. We test the algorithm on IBM-Q devices and demonstrate the relaxation of system spins to ferromagnetic and antiferromagnetic ordering, controlled by the definition of the system Hamiltonian. The ordering is stable as long as the algorithm is run. We are able to perform cooling and state stabilization for global systems of up to three system spins and four auxiliary spins. Our work paves the way for useful quantum simulations of many-body quantum systems on near-term quantum computers.

DOI: 10.1103/PhysRevA.111.022614

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.022614