



01491nas a2200157   4500008004100000245005900041210005800100260001300158490000800171520102800179100001901207700002201226700002001248700002801268856003701296       2023                        eng d00aNon-Abelian symmetry can increase entanglement entropy0 aNonAbelian symmetry can increase entanglement entropy  c1/3/20230 v1073 a<p>The pillars of quantum theory include entanglement and operators&#39; failure to commute. The Page curve quantifies the bipartite entanglement of a many-body system in a random pure state. This entanglement is known to decrease if one constrains extensive observables that commute with each other (Abelian ``charges&#39;&#39;). Non-Abelian charges, which fail to commute with each other, are of current interest in quantum thermodynamics. For example, noncommuting charges were shown to reduce entropy-production rates and may enhance finite-size deviations from eigenstate thermalization. Bridging quantum thermodynamics to many-body physics, we quantify the effects of charges&#39; noncommutation -- of a symmetry&#39;s non-Abelian nature -- on Page curves. First, we construct two models that are closely analogous but differ in whether their charges commute. We show analytically and numerically that the noncommuting-charge case has more entanglement. Hence charges&#39; noncommutation can promote entanglement.</p>1 aMajidy, Shayan1 aLasek, Aleksander1 aHuse, David, A.1 aHalpern, Nicole, Yunger  uhttps://arxiv.org/abs/2209.1430301518nas a2200169   4500008004100000245007200041210006900113260001300182520098500195100001901180700002501199700002201224700002101246700001601267700002801283856003701311       2023                        eng d00aNoncommuting conserved charges in quantum thermodynamics and beyond0 aNoncommuting conserved charges in quantum thermodynamics and bey  c9/7/20233 a<p>Thermodynamic systems typically conserve quantities (&quot;charges&quot;) such as energy and particle number. The charges are often assumed implicitly to commute with each other. Yet quantum phenomena such as uncertainty relations rely on observables&#39; failure to commute. How do noncommuting charges affect thermodynamic phenomena? This question, upon arising at the intersection of quantum information theory and thermodynamics, spread recently across many-body physics. Charges&#39; noncommutation has been found to invalidate derivations of the thermal state&#39;s form, decrease entropy production, conflict with the eigenstate thermalization hypothesis, and more. This Perspective surveys key results in, opportunities for, and work adjacent to the quantum thermodynamics of noncommuting charges. Open problems include a conceptual puzzle: Evidence suggests that noncommuting charges may hinder thermalization in some ways while enhancing thermalization in others.</p>1 aMajidy, Shayan1 aBraasch, William, F.1 aLasek, Aleksander1 aUpadhyaya, Twesh1 aKalev, Amir1 aHalpern, Nicole, Yunger  uhttps://arxiv.org/abs/2306.00054