Dr. Niklas Witt

• Strongly correlated electron systems
• Unconventional superconductivity (characterization, pairing mechanisms, limitations and beyond)
• BCS-BEC crossover in condensed matter systems
• Interplay of quantum geometry and correlation effects
• Fullerides, Nickelates, (twisted) 2D systems
• Development of many-body methods (FLEX, (C)DMFT, low-rank compression, ...)

Electron correlations and unconventional superconductivity in realistic solid-state materials and heterostructures

[1]. Bypassing the lattice BCS–BEC crossover in strongly correlated superconductors through multiorbital physics, Niklas Witt, Yusuke Nomura, Sergey Brener, Ryotaro Arita, Alexander I Lichtenstein, Tim O Wehling, npj Quantum Materials 9, 1 (2024).

[2]. Quenched Pair Breaking by Interlayer Correlations as a Key to Superconductivity in La₃Ni₂O₇, Siheon Ryee, Niklas Witt, Tim O. Wehling, Physical Review Letters 133, 096002 (2024).

[3]. sparse-ir: Optimal compression and sparse sampling of many-body propagators, Markus Wallerberger, Samuel Badr, Shintaro Hoshino, Sebastian Huber, Fumiya Kakizawa, Takashi Koretsune, Yuki Nagai, Kosuke Nogaki, Takuya Nomoto, Hitoshi Mori, Junya Otsuki, Soshun Ozaki, Thomas Plaikner, Rihito Sakurai, Constanze Vogel, Niklas Witt, Kazuyoshi Yoshimi, Hiroshi Shinaoka, SoftwareX 21, 101266 (2023).

• since 2024: Postdoctoral Researcher, Julius-Maximilians-Universität Würzburg
• 2020-2024: Dr. rer. nat., University of Hamburg
• 2018-2020: M.Sc. in Physics, University of Bremen
• 2015-2018: B.Sc. in Physics, University of Bremen