Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems 3 (jointly with DY)

TT 45.7: Vortrag

Dienstag, 17. März 2015, 15:30–15:45, H 3010

Thermalization rates in a 1d Fermi-Hubbard model with slightly broken integrability for various fillings — •Fabian Biebl and Stefan Kehrein — Institut für Theoretische Physik, Georg-August-Universität Göttingen, D-37077 Göttingen, Germany

Understanding relaxation in quantum systems is essential to determine whether an experimental setup can be described by equilibrium concepts. For example integrable systems do not thermalize, but develop into non-thermal steady states. By slightly breaking integrability, thermalization of such non-thermal (prethermalized) states becomes possible. An important question is to identify the corresponding timescale for thermalization due to the breaking of integrability.

We investigate this question for a fermionic Hubbard chain in the thermodynamic limit. The integrability breaking term is a small next to nearest neighbor hopping term [1,2]. The thermalization timescale is extracted from the quantum Boltzmann equation and depends strongly on temperature, especially when one goes away from half filling. The dependence on filling is connected to Umklapp-processes and we study this dependence systematically.

[1] M. L. R. Fuerst et al., Phys. Rev. E 86, 031122 (2012).

[2] M. L. R. Fuerst et al., Phys. Rev. E 88, 012108 (2013).