Kubo's response theory and bosonization with a background gauge field and irrelevant perturbations

Abstract

Using conformal field theory calculations of the energy spectrum, within the XXZ model we investigate effects of the flux insertion and the Umklapp term. We discuss two approaches to the evaluation of the Drude weight, the first corresponding to the linear response theory and the second corresponding to the twisted boson theory with the Umklapp term. Divergences obtained in the context of the former contradict the Bethe ansatz results, with the two approaches coinciding for the free fermion point only. The origin of this discrepancy is in the different order in which the Umklapp term and the flux insertion are treated, where the marginal perturbation should be considered before the irrelevant. We calculate the scaling of the conductivity with system size and temperature in the long-wave limit.

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References in corpus (5)

• Conservation laws, integrability and transport in one-dimensional quantum systems
• The Luttinger liquid and integrable models
• Quantum rings for beginners II: Bosons versus fermions
• Exact results for nonlinear Drude weights in the spin-1/2 XXZ chain
• The spin Drude weight of the spin-1/2 $XXZ$ chain: An analytic finite size study

Cited by in corpus (3)

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