Verdel Roberto, Zhu Guo-Yi, Heyl Markus
Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany.
The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy.
Phys Rev Lett. 2023 Dec 8;131(23):230402. doi: 10.1103/PhysRevLett.131.230402.
The fission of a string connecting two charges is an astounding phenomenon in confining gauge theories. The dynamics of this process have been studied intensively in recent years, with plenty of numerical results yielding a dichotomy: the confining string can decay relatively fast or persist up to extremely long times. Here, we put forward a dynamical localization transition as the mechanism underlying this dichotomy. To this end, we derive an effective string breaking description in the light-meson sector of a confined spin chain and show that the problem can be regarded as a dynamical localization transition in Fock space. Fast and suppressed string breaking dynamics are identified with delocalized and localized behavior, respectively. We then provide a further reduction of the dynamical string breaking problem onto a quantum impurity model, where the string is represented as an "impurity" immersed in a meson bath. It is shown that this model features a localization-delocalization transition, giving a general and simple physical basis to understand the qualitatively distinct string breaking regimes. These findings are directly relevant for a wider class of confining lattice models in any dimension and could be realized on present-day Rydberg quantum simulators.
在禁闭规范理论中，连接两个电荷的弦的裂变是一种惊人的现象。近年来，人们对这一过程的动力学进行了深入研究，大量的数值结果产生了一种二分法：禁闭弦可以相对快速地衰变，或者持续极长的时间。在这里，我们提出一种动力学局域化转变作为这种二分法的潜在机制。为此，我们在禁闭自旋链的轻介子扇区中推导了一种有效的弦断裂描述，并表明该问题可以被视为福克空间中的动力学局域化转变。快速和受抑制的弦断裂动力学分别与离域和局域行为相关。然后，我们将动力学弦断裂问题进一步简化为一个量子杂质模型，其中弦被表示为沉浸在介子浴中的“杂质”。结果表明，该模型具有局域化 - 离域化转变，为理解性质上不同的弦断裂机制提供了一个通用且简单的物理基础。这些发现与任何维度的更广泛的禁闭晶格模型直接相关，并且可以在当今的里德堡量子模拟器上实现。
