Theoretical Particle Physics Seminar – Niels Bohr Institute - University of Copenhagen

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Theoretical Particle Physics Seminar

Speaker: Uwe-Jens Wiese (University of Bern)

Title: From QCD to Lightly Doped Antiferromagnets:  Effective Field Theories for Magnons and Holes

Abstract:  Lightly doped antiferromagnets are the precursors of high-temperature
superconductors. The Goldstone bosons of antiferromagnetism are spin
waves or magnons. In analogy to baryon chiral perturbation theory for
the pseudo-Nambu-Goldstone pions and the nucleons in QCD, systematic
low-energy effective field theories are developed for magnons and
holes in lightly doped antiferromagnets, both on the square and on
the honeycomb lattice. Two-hole states bound by magnon-exchange are
a condensed matter analogue of the deuteron, while spiral phases of
the staggered magnetization are analogous to pion condensation in
dense nuclear matter. The determination of the low-energy parameters
of the effective theory by high-precision numerical simulations of
the t-J model is also discussed.