Drude weight in non solvable quantum spin chains
G. Benfatto, Vieri Mastropietro
For a quantum spin chain or 1D fermionic system, we prove that the Drude weight D verifies the universal Luttinger liquid relation v 2 s = D/κ, where κ is the susceptibility and vs is the Fermi velocity. This result is proved by rigorous Renormalization Group methods and is true for any weakly interacting system, regardless its integrablity. This paper, combined with [1], completes the proof of the Luttinger liquid conjecture for such systems. 1 Introduction and main result Quantum spin chains and one dimensional Fermi systems have been the subject of an intense theoretical investigation for decades, either for their remarkable properties or for the fact that they can be experimentally realized in systems like quantum spin chain models (KCuF3) [2] or carbon nanotubes [3]. We consider a quantum spin chain model
•Jan 1, 2010•11 citations