ARPES spectra reveal parton properties of antiferromagnets
Post date: Jan 17, 2020
Understanding the nature of charge carriers in strongly correlated materials has been a long-standing problem. One of the most direct methods to study them, is ARPES spectroscopy. Even in idealized settings, such as at infinitesimal doping in a clean toy model, ARPES spectra remain debated. We study one-hole ARPES specta in the clean 2D t-J model -- a scenario expected to be accurately tested with ultracold atom experiments in the near future.
We report new evidence for the parton structure of charge charriers in doped quantum magnets: Much like mesons and baryons are composites of confined quarks, mobile holes behave like mesonic bound states of spinons and chargons. Much less is known about these partons in anti-ferromagnets, however. This is where our study comes in: We find that various features in the ARPES spectra at strong coupling can reveal direct clues about the proporties of the constiuting partons.
In addition, our microscopic picture provides a new perspective on the Fermi-arcs observed in the pseudogap phase of high-Tc cuprate compounds: We suggest a microscopic explanation for the strong suppression of spectral weight on the backside of a putative Fermi surface.
Looking beyond these models, our findings also suggest a new way to directly probe the nature of spinons in strongly frustrated quantum anti-ferromagnets and quantum spin liquids.
Our work has been published in PRB:
A. Bohrdt, E. Demler, F. Pollmann, M. Knap, F. Grusdt, Parton theory of ARPES spectra in anti-ferromagnetic Mott insulators, Phys. Rev. B 102, 035139 (2020).