Ali Ahmad Shadi, Galley Thomas D, Höhn Philipp A, Lock Maximilian P E, Smith Alexander R H
Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA.
Perimeter Institute for Theoretical Physics, 31 Caroline St N, Waterloo, Ontario, N2L 2Y5 Canada.
Phys Rev Lett. 2022 Apr 29;128(17):170401. doi: 10.1103/PhysRevLett.128.170401.
One of the most basic notions in physics is the partitioning of a system into subsystems and the study of correlations among its parts. In this Letter, we explore this notion in the context of quantum reference frame (QRF) covariance, in which this partitioning is subject to a symmetry constraint. We demonstrate that different reference frame perspectives induce different sets of subsystem observable algebras, which leads to a gauge-invariant, frame-dependent notion of subsystems and entanglement. We further demonstrate that subalgebras which commute before imposing the symmetry constraint can translate into noncommuting algebras in a given QRF perspective after symmetry imposition. Such a QRF perspective does not inherit the distinction between subsystems in terms of the corresponding tensor factorizability of the kinematical Hilbert space and observable algebra. Since the condition for this to occur is contingent on the choice of QRF, the notion of subsystem locality is frame dependent.
物理学中最基本的概念之一是将一个系统划分为子系统，并研究其各部分之间的相关性。在本信函中，我们在量子参考系（QRF）协变性的背景下探讨这一概念，其中这种划分受到对称性约束。我们证明，不同的参考系视角会诱导出不同的子系统可观测量代数集，这导致了一种规范不变的、依赖于参考系的子系统和纠缠概念。我们进一步证明，在施加对称性约束之前相互对易的子代数，在施加对称性后，在给定的QRF视角下可能会转化为非对易代数。这样的QRF视角不会继承根据运动学希尔伯特空间和可观测量代数的相应张量可分解性来区分子系统的特性。由于这种情况发生的条件取决于QRF的选择，子系统局域性的概念是依赖于参考系的。
