SKM 2021 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 9: Poster Session: Correlated Electrons

TT 9.36: Poster

Dienstag, 28. September 2021, 13:30–16:00, P

Orientational order parameters for arbitrary quantum systems* — •Michael te Vrugt and Raphael Wittkowski — Institut für Theoretische Physik, Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany

The concept of quantum-mechanical nematic order, which is important in systems such as superconductors, is based on an analogy to classical liquid crystals, where order parameters are obtained through orientational expansions [1]. We generalize this method to quantum mechanics based on an expansion of Wigner functions [2]. This provides a systematic framework for the derivation of quantum order parameters, which unifies all known types of quantum orientational order into one framework and has a natural connection to the classical case. The formalism recovers the standard definitions for spin systems. For Fermi liquids, the formalism reveals the nonequivalence of various definitions of the order parameter used in the literature.

Funded by the Deutsche Forschungsgemeinschaft (DFG) - WI 4170/3-1
[1] M. te Vrugt, R. Wittkowski, AIP Adv. 10, 035106 (2020)
[2] M. te Vrugt, R. Wittkowski, Ann. Phys. (Berl.) 532, 2000266 (2020)