Quantum Electrodynamics in Dimensions as the Organizing Principle of a Triangular Lattice Antiferromagnet

by Andreas Martin Läuchli Herzig (PSI - Paul Scherrer Institut / EPFL)

Tuesday 11 Jun 2024, 11:00 → 12:00 Europe/Zurich

WHGA/121

Quantum electrodynamics in 2+1 dimensions (QED_3) has been proposed as a critical field theory describing 
the low-energy effective theory of a putative algebraic Dirac spin liquid or of quantum phase transitions in 
two-dimensional frustrated magnets. We provide compelling evidence that the intricate spectrum of excitations 
of the elementary but strongly frustrated 𝐽1−𝐽2 Heisenberg model on the triangular lattice is in one-to-one 
correspondence to a zoo of excitations from QED3, in the quantum spin liquid regime. This evidence includes 
a large manifold of explicitly constructed monopole and bilinear excitations of QED3, which is thus shown to 
serve as an organizing principle of phases of matter in triangular lattice antiferromagnets and their low-lying 
excitations. Our results are obtained by comparing ansatz wave functions from a parton construction to exact 
eigenstates obtained using large-scale exact diagonalization up to 𝑁=48 sites.