Non-perturbative effective field theory for two-leg antiferromagnetic spin ladders
Abstract
We study the long wavelength limit of a spin 1/2 Heisenberg antiferromagnetic two-leg ladder, treating the interchain coupling in a non-perturbative way. We perform a mean field analysis and then include exactly the fluctuations. This allows for a discussion of the phase diagram of the system and provides an effective field theory for the low energy excitations. The coset fermionic Lagrangian obtained corresponds to a perturbed SU(4)1/U(1) Conformal Field Theory (CFT). This effective theory is naturally embedded in a SU(2)2 x Z2 CFT, where perturbations are easily identified in terms of conformal operators in the two sectors. Crossed and zig-zag ladders are also discussed using the same approach.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.