近日，德国波恩大学Johann Kroha团队报道了块状凝聚态系统中本征非厄米相变的发现。相关论文于2026年9月10日发表在《科学》杂志上。

在常规相变过程中，系统保持热平衡。然而，当系统被驱动远离平衡时，可能出现非厄米相变；此时，发生定性变化的是动力学行为而非稳态性质，且这种变化发生在临界的所谓例外点。

研究组在一个体凝聚态系统中实验实现了非厄米相变。光激发在铁磁性一氧化铕中产生载流子。在与向铁磁有序的厄米相变随温度变化的相互作用中，弛豫动力学发生了非厄米变化，这在其时间分辨反射数据中表现为从双指数实衰减到单指数复衰减的转变。研究组理论对这种现象进行了建模，并表明非厄米相变可能普遍出现于体凝聚态物质中。

附：英文原文

Title: Discovery of an intrinsic non-Hermitian phase transition in a bulk condensed-matter system

Author: Jingwen Li, Michael Turaev, Masakazu Matsubara, Kristin Kliemt, Cornelius Krellner, Shovon Pal, Manfred Fiebig, Johann Kroha

Issue&Volume: 2026-09-10

Abstract: Across regular phase transitions, systems remain in thermal equilibrium. However, when a system is driven far from equilibrium, non-Hermitian phase transitions may arise where the dynamical behavior—rather than steady properties—undergoes a qualitative change at a critical, so-called exceptional point. We experimentally realize a non-Hermitian phase transition in a bulk condensed-matter system. Optical excitation creates charge carriers in ferromagnetic europium monoxide. In a temperature-dependent interplay with the Hermitian transition to ferromagnetic order, a non-Hermitian change of the relaxation dynamics occurs, manifesting in our time-resolved reflection data as the transition from biexponential real to single-exponential complex decay. Our theory models this behavior and suggests that non-Hermitian phase transitions may generically emerge in bulk condensed matter.

DOI: 10.1126/science.ady4670

Source: https://www.science.org/doi/10.1126/science.ady4670