Regensburg 2025 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 43: Correlated Electrons: Other Theoretical Topics
TT 43.3: Vortrag
Donnerstag, 20. März 2025, 10:00–10:15, H33
Anomalous quantum oscillations from boson-mediated interband scattering — •Léo Mangeolle1,2 and Johannes Knolle1,2,3 — 1Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany — 2Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, 80799 München, Germany — 3Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
Quantum oscillations (QO) in metals refer to the periodic variation of thermodynamic and transport properties as a function of inverse applied magnetic field. QO frequencies are normally associated with semi-classical trajectories of Fermi surface orbits but recent experiments challenge the canonical description. We develop a theory of composite frequency quantum oscillations (CFQO) in two-dimensional Fermi liquids with several Fermi surfaces and interband scattering mediated by a dynamical boson, e.g. phonons or spin fluctuations. Specifically, we show that CFQO arise from oscillations in the fermionic self-energy with anomalous frequency splitting and distinct strongly non-Lifshitz-Kosevich temperature dependencies. Our theory goes beyond the framework of semi-classical Fermi surface trajectories highlighting the role of many-body effects. We provide experimental predictions and discuss the effect of non-equilibrium boson occupation in driven systems.
Keywords: quantum oscillations; de Haas-van Alphen effect; Shubnikov-de Haas effect; electron-phonon coupling