Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 17: Poster Session: Correlated Electrons 1
TT 17.18: Poster
Montag, 1. April 2019, 15:00–18:30, Poster D
Quantum Monte Carlo simulations of quantum critical fermions — •Carsten Bauer1, Yoni Schattner2, Erez Berg3, and Simon Trebst1 — 1University of Cologne, Germany — 2Stanford University, USA — 3The Weizmann Institute of Science, Israel
While quantum critical phenomena in insulators are fairly well understood, their metallic counterparts pose a substantial theoretical challenge since the order parameter fluctuations can interact with gapless excitations on a Fermi surface. When driving a metal through a phase transition, this interplay can give rise to unconventional superconductivity and “strange metal” behavior and might therefore serve as a microscopic model for some of the rich physics of high-Tc materials.
Fortunately, certain classes of metallic quantum critical points can be analyzed by determinant quantum Monte Carlo as one can circumvent the notorious “sign problem” and retain polynomial efficiency. I will show numerically exact studies of two dimensional metals at the verge of an antiferromagnetic transition indicating Landau-damped dynamics of the order parameter and a breakdown of Fermi liquid theory. I will further demonstrate that machine learning techniques, such as quantum loop topography and convolutional neural networks, can be utilized to probe transport and identify phase transitions in such many-particle systems.