Families of quasi-local conservation laws and quantum spin transport
arXiv:1306.4498 · doi:10.1103/PhysRevLett.111.057203
Abstract
For fundamental integrable quantum chains with deformed symmetries we outline a general procedure for defining a continuous family of quasi-local operators whose time-derivative is supported near the two boundary sites only. The program is implemented for a spin 1/2 XXZ chain, resulting in improved rigorous estimates for the high temperature spin Drude weight.
4+eps pages in RevTex, with 1 pdf figure