BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250810T173638EDT-3064FUBKbU@132.216.98.100 DTSTAMP:20250810T213638Z DESCRIPTION:PHYSICS SEMINAR\n\nTitle: Entanglement and separability of Rokh sar-Kivelson and resonating valence-bond states\n\nAbstract: Entanglement and separability are two opposite yet intertwined notions in quantum mecha nics. A quantum state is said to be entangled if it is not separable\, and vice versa. Quantifying how entangled two subsystems are remains a challe nging problem\, which has led to important insights in the context of quan tum many-body systems. In this talk\, we discuss entanglement and separabi lity of dimer Rokhsar-Kivelson (RK) states and resonating valence-bond (RV B) states. For dimer RK states on general tilable graphs\, we prove the ex act separability of the reduced density matrix of two disconnected subsyst ems\, implying the absence of entanglement between the subsystems. For RVB states\, we show separability for disconnected subsystems up to exponenti ally small terms in the distance d between the two subsystems. We argue th at separability does hold in the scaling limit\, even for arbitrarily smal l ratio d/L\, where L is the characteristic size of the subsystems. Our re sults hold irrespective of the underlying graph (which include square and triangular lattices)\, and hence suggest that separability (up to exponent ially small terms) between disjoint regions is a universal feature of RVB states. In the case of adjacent subsystems for the RK states\, we derive e xact results for the logarithmic negativity in terms of partition function s of the underlying statistical model\, and recover the known result for t he Rényi-1/2 entropy in the limit of complementary subsystems.\n Based on j oint work with Clément Berthier and William Witczak-Krempa\, arXiv: 2212.1 1740\n\nCRM-Salle 4336-4384\, Pav. André Aisenstadt\n DTSTART:20230207T203000Z DTEND:20230207T213000Z SUMMARY:Gillez Parez\, CRM-Université de Montréal URL:/mathstat/channels/event/gillez-parez-crm-universi te-de-montreal-345747 END:VEVENT END:VCALENDAR