@article {3002, title = {Experimental observation of thermalisation with noncommuting charges}, year = {2022}, month = {2/9/2022}, abstract = {

Quantum simulators have recently enabled experimental observations of quantum many-body systems\&$\#$39; internal thermalisation. Often, the global energy and particle number are conserved, and the system is prepared with a well-defined particle number - in a microcanonical subspace. However, quantum evolution can also conserve quantities, or charges, that fail to commute with each other. Noncommuting charges have recently emerged as a subfield at the intersection of quantum thermodynamics and quantum information. Until now, this subfield has remained theoretical. We initiate the experimental testing of its predictions, with a trapped-ion simulator. We prepare 6-15 spins in an approximate microcanonical subspace, a generalisation of the microcanonical subspace for accommodating noncommuting charges, which cannot necessarily have well-defined nontrivial values simultaneously. We simulate a Heisenberg evolution using laser-induced entangling interactions and collective spin rotations. The noncommuting charges are the three spin components. We find that small subsystems equilibrate to near a recently predicted non-Abelian thermal state. This work bridges quantum many-body simulators to the quantum thermodynamics of noncommuting charges, whose predictions can now be tested.

}, keywords = {FOS: Physical sciences, Quantum Physics (quant-ph), Statistical Mechanics (cond-mat.stat-mech)}, doi = {10.48550/ARXIV.2202.04652}, url = {https://arxiv.org/abs/2202.04652}, author = {Kranzl, Florian and Lasek, Aleksander and Joshi, Manoj K. and Kalev, Amir and Blatt, Rainer and Roos, Christian F. and Nicole Yunger Halpern} }