SKM 2023 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 23: Poster Magnetism I

MA 23.33: Poster

Dienstag, 28. März 2023, 17:00–19:00, P1

Magnon excitations in two-dimensional doped Antiferromagnets — •Pit Bermes — Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, München D-80333, Germany — Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, D-80799 München, Germany

When a mobile hole is doped into an antiferromagnet, its movement will distort the surrounding magnetic order and yield a magnetic polaron. The resulting complex interplay of spin and charge degrees of freedom gives rise to very rich physics and is widely believed to be at the heart of high-temperature superconductivity in cuprates. Although the parton theory has been successful in describing many properties of these magnetic polarons, it is still unclear how these couple to the collective magnon excitations. In this paper, we derive this effective coupling between the polaron and magnons and their influences on the polaron's properties. We therefore start from a single hole doped into an AFM described in the aforementioned polaron model by a 'geometric string' and will then introduce magnon excitations through a generalized 1/S expansion to arrive at an effective Hamiltonian. After making a Born-Oppenheimer-type approximation, this system will be solved using the self-consistent Born approximation to extract the renormalized polaron properties, like its dispersion relation and the single-particle spectrum.