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TT: Fachverband Tiefe Temperaturen
TT 24: Quantum-Critical Phenomena
TT 24.7: Talk
Tuesday, March 19, 2024, 11:00–11:15, H 2053
From Nordic Walking in Wess-Zumino-Witten Theory to Deconfined Pseudocriticality — •Bilal Hawashin1, Astrid Eichhorn2, Lukas Janssen3, Michael Scherer1, and Shouryya Ray2 — 1Institut für Theoretische Physik III, Ruhr-Universität Bochum, 44801 Bochum, Germany — 2CP3-Origins, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark — 3Institut für Theoretische Physik and Würzburg-Dresden Cluster of Excellence ct.qmat, TU Dresden, 01062 Dresden, Germany
An exciting class of non-Landau transitions are deconfined quantum critical points (DQCP) which exhibit emergent fractional excitations and gauge fields at criticality. The primary example in the study of DQCPs has been a system of half-integer spins on a square lattice with competing interactions. Whether or not this system shows true criticality is a major open question in the field. In fact, numerical simulations for this model provide evidence for weak-first order behavior. The effective field theory describing the behaviour between those orders is a 3D Wess-Zumino-Witten theory with target manifold S4. I will discuss a first study of this model using the non-perturbative functional renormalization group. We show that the Wess-Zumino-Witten term gives rise to two possible mechanisms explaining pseudocriticality and drifting exponents: (1) the well-known Walking mechanism and (2) a new mechanism, dubbed Nordic Walking. We provide an estimate for effective thermodynamic critical exponents and their drifts as a function of system size.
Keywords: Deconfined quantum critical points; Renormalization group methods; Weakly first-order transitions; Wess-Zumino-Witten Theory; Complex Conformal Field Theory