Berlin 2018 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 88: Quantum-Critical Phenomena III
TT 88.3: Talk
Thursday, March 15, 2018, 12:00–12:15, H 3010
Quantum critical behavior of Dirac systems at higher-loop order — •Bernhard Ihrig1, Michael Scherer1, Luminita Mihaila2, and Nikolai Zerf2 — 1Universität Köln — 2Universität Heidelberg
Dirac fermions appear as quasi-particle excitations in many different condensed-matter systems. They display various quantum transitions which represent unconventional universality classes related to variants of Gross-Neveu-Yukawa models. For the first time, we study these models – at three- and four-loop order, and compute critical exponents in 4−є dimensions for general number of fermion flavors.We apply the computed series for the exponents and their Padé approximants to several phase transitions of current interest: metal-insulator transitions of spin-1/2 and spinless fermions on the honeycomb lattice, emergent supersymmetric surface field theory in topological phases, as well as dualities in a deconfined quantum criticality scenario. Comparison with the results of other analytical and numerical methods is discussed.