Regensburg 2019 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 4: Nonequilibrium Quantum Many-Body Systems 1 (joint session TT/DY)

DY 4.6: Vortrag

Montag, 1. April 2019, 10:45–11:00, H22

Dynamics of densities and currents in spin ladders — •Jonas Richter¹, Fengping Jin², Lars Knipschild¹, Jacek Herbrych³, Hans De Raedt⁴, Kristel Michielsen², Jochen Gemmer¹, and Robin Steinigeweg¹ — ¹University of Osnabrück, Germany — ²Forschungszentrum Jülich, Germany — ³The University of Tennessee, USA — ⁴University of Groningen, The Netherlands

The impact of integrability or nonintegrability on the dynamics of isolated quantum systems is a longstanding issue. For integrable models, a macroscopic set of (quasi)local conservation laws can lead to partially conserved currents and ballistic transport. In generic situations, however, integrability is lifted due to various perturbations and currents are expected to decay. Still, since the dynamics of interacting quantum many-body systems poses a formidable challenge to theory and numerics, it remains open whether nonintegrability as such already implies the emergence of diffusion. In this context, we study the dynamics of spin and energy in the two-leg spin-1/2 ladder with up to 40 lattice sites, using an efficient pure-state approach based on the concept of typicality. We discuss correlation functions in real and momentum space, and in the time and frequency domain, providing a comprehensive picture of high-temperature dynamics in this archetypal nonintegrable quantum model. Particularly, we unveil the occurence of diffusion for both spin and energy.
J. Richter et al., Phys. Rev. B 97, 174430 (2018)
J. Richter et al., arXiv:1811.02806