Dresden 2014 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 25: Transport: Quantum dots, quantum wires, point contacts II (organized by TT)
HL 25.5: Talk
Monday, March 31, 2014, 17:15–17:30, HSZ 204
Hierarchical Equation of Motion Investigation of Decoherence and Relaxation Dynamics in Nonequilibrium Transport through Interacting Quantum Dots — •Rainer Härtle1,2, Guy Cohen3, David R. Reichman3, and Andrew J. Millis2 — 1Institut für theoretische Physik, Georg-August-Universität Göttingen, Göttingen, Germany — 2Department of Physics, Columbia Universtiy, New York, USA — 3Department of Chemistry, Columbia Universtiy, New York, USA
A recently developed hierarchical quantum master equation approach [1,2] is used to investigate nonequilibrium electron transport through an interacting double quantum dot system in the regime where the inter-dot coupling is weaker than the coupling to the electrodes. The corresponding eigenstates provide tunneling paths that may interfere constructively or destructively, depending on the energy of the tunneling electrons [3]. Electron-electron interactions are shown to quench these interference effects in bias-voltage dependent ways, leading, in particular, to negative differential resistance, population inversion and an enhanced broadening of resonances in the respective transport characteristics [2]. Relaxation times are found to be very long, and to be correlated with very slow dynamics of the inter-dot coherences. The ability of the hierarchical quantum master equation approach to access very long time scales is crucial for the study of this physics.
[1] J. Jin et al., J. Chem. Phys. 128, 234703 (2008).
[2] R. Härtle et al., arXiv:1309.1170 (2013)
[3] R. Härtle et al., Phys. Rev. B 87, 085422 (2013)