



@article {3055,
	title = {Non-Abelian eigenstate thermalization hypothesis},
	journal = {Phys. Rev. Lett.},
	volume = {130},
	year = {2023},
	month = {4/6/2023},
	chapter = {140402},
	abstract = {<p>The eigenstate thermalization hypothesis (ETH) explains why chaotic quantum many-body systems thermalize internally if the Hamiltonian lacks symmetries. If the Hamiltonian conserves one quantity (\&quot;charge\&quot;), the ETH implies thermalization within a charge sector -- in a microcanonical subspace. But quantum systems can have charges that fail to commute with each other and so share no eigenbasis; microcanonical subspaces may not exist. Furthermore, the Hamiltonian will have degeneracies, so the ETH need not imply thermalization. We adapt the ETH to noncommuting charges by positing a non-Abelian ETH and invoking the approximate microcanonical subspace introduced in quantum thermodynamics. Illustrating with SU(2) symmetry, we apply the non-Abelian ETH in calculating local observables\&$\#$39; time-averaged and thermal expectation values. In many cases, we prove, the time average thermalizes. However, we also find cases in which, under a physically reasonable assumption, the time average converges to the thermal average unusually slowly as a function of the global-system size. This work extends the ETH, a cornerstone of many-body physics, to noncommuting charges, recently a subject of intense activity in quantum thermodynamics.</p>},
	keywords = {FOS: Physical sciences, High Energy Physics - Theory (hep-th), Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph), Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el)},
	doi = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.130.140402},
	url = {https://arxiv.org/abs/2206.05310},
	author = {Murthy, Chaitanya and Babakhani, Arman and Iniguez, Fernando and Srednicki, Mark and Nicole Yunger Halpern}
}
@article {3002,
	title = {Experimental observation of thermalisation with noncommuting charges},
	year = {2022},
	month = {2/9/2022},
	abstract = {<p>Quantum simulators have recently enabled experimental observations of quantum many-body systems\&$\#$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.</p>},
	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}
}
