Novel polarons in Fermi-Hubbard systems

 

In the context of doped Mott insulators, magnetic polarons are quasiparticles that usually arise from an interplay between the kinetic energy of doped charge carriers and super exchange spin interactions. In this talk, we consider extensions to this paradigmatic model and introduce novel techniques to characterize many body phases in optical lattice simulators.

Firstly, we report on experiments in a Triangular lattice Hubbard simulator which reveal the presence of itinerant spin polarons bound via kinetic magnetism, paving the way for exploring potential mechanisms for hole pairing and superconductivity in frustrated systems.

To characterize spin-dopant interactions in further detail, we apply two-photon Raman spectroscopy to inject single magnons into a hole-doped band insulator, finding a regime where hole scattering events coherently dress the magnetic excitation, resulting in a novel quasiparticle: the magnon-polaron.

We conclude with preliminary results towards a general scheme for momentum resolved spectroscopy in optical lattices.