Abstract:
Nonparallel boundary magnetic fields can induce a longitudinal (spin) current in a quantum spin chain. We use functional approaches to formulate the spectral problem for the spin-1/2 Heisenberg model subject to a class of integrable boundary conditions in terms of an infinite hierarchy of nonlinear integral equations. From these equations, we compute finite-size corrections to the ground-state energy of the antiferromagnetic chain and the induced spin current for a certain range of boundary parameters.
Keywords:
integrable spin chain, boundary field, Bethe ansatz, Y system.
Citation:
H. Frahm, J. H. Grelik, A. Seel, “Persistent currents in open spin chains”, TMF, 171:2 (2012), 340–352; Theoret. and Math. Phys., 171:2 (2012), 715–724