SKM 2021 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 15: Many-Body Quantum Dynamics II (joint session DY/TT)

TT 15.2: Vortrag

Donnerstag, 30. September 2021, 10:15–10:30, H2

An SYK-inspired model with density-density interactions — •Johannes Dieplinger¹, Soumya Bera², and Ferdinand Evers¹ — ¹Institute of Theoretical Physics, University of Regensburg, D-93040, Germany — ²Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India

Strong electron-electron interactions are challenging to capture theoretically. A rare example of an analytically tractable model is the Sachdev-Ye-Kitaev (SYK) model, which owes its tractability to the structureless and therefore artificial design: interactions are restricted to two body terms, whose matrix elements are randomly chosen and therefore do not commute with the local density, a fundamental symmetry of realistic electron-electron interactions. We here investigate a derivative of the SYK model, restoring this fundamental symmetry [1]. It features density-density-type interactions as well as a randomized single body term. We present numerical evidence that this model has a rich phase structure, featuring two integrable phases separated by several intermediate phases, including a chaotic one. The latter exhibits several key characterstics of the SYK model including the spectral and wave function statistics and therefore should be adiabatically connected to the non-Fermi liquid phase of the original SYK model. Thus, the presented model provides a further element for bridging the SYK-model and microscopic realism.

[1] J. Dieplinger, S. Bera, F. Evers, Annals of Physics, 168503 (2021)