Hole Dynamics in an Antiferromagnet

Post date: June 12, 2020

The interplay of spin and charge degrees of freedom in a doped anti-ferromagnet is a fundamental ingredient that gives rise to the exotic physical behavior observed in these systems. This includes non-Fermi liquid transport properties, the pseudogap features in ARPES spectra, ...

We study this problem on the most fundamental level, in a time- and space- resolved way in a clean 2D Hubbard / t-J model. In a recent collaboration with Harvard's Greiner lab we observed the dynamical formation of a magnetic polaron, after releasing an initially pinned hole inside an extended anti-ferromagnet.

In agreement with our earlier theoretical simulations (including TUM/MPQ collaborations) we find a two-stage dynamical process: A fast initial spreading followed by a slow expansion which depends on the strength of the spin-exchange coupling. The collection of theoretical and experimental observation can be largely explained - even quantitatively - by a microscopic spinon-chargon description of the dynamically evolving magnetic polaron.

Our work consists of a series of theoretical and experimental papers which can be found online:

  • Geoffrey Ji, Muqing Xu, Lev Haldar Kendrick, Christie S. Chiu, Justus C. Brüggenjürgen, Daniel Greif, Annabelle Bohrdt, Fabian Grusdt, Eugene Demler, Martin Lebrat, and Markus Greiner, "Dynamical interplay between a single hole and a Hubbard antiferromagnet." arXiv:2006.06672.

  • Annabelle Bohrdt, Fabian Grusdt, and Michael Knap. "Dynamical formation of a magnetic polaron in a two-dimensional quantum antiferromagnet." New J. Phys. 22, 123023 (2020).

  • Claudius Hubig, Annabelle Bohrdt, Michael Knap, Fabian Grusdt and J. Ignacio Cirac. "Evaluation of time-dependent correlators after a local quench in iPEPS: hole motion in the t-J model." SciPost Phys. 8, 021 (2020).

  • Fabian Grusdt, Marton Kanasz-Nagy, Annabelle Bohrdt, Christie S. Chiu, Geoffrey Ji, Markus Greiner, Daniel Greif, and Eugene Demler. 3/21/2018. “Parton Theory of Magnetic Polarons: Mesonic Resonances and Signatures in Dynamics.Physical Review X, 8, 011046.