Dresden 2009 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 11: Transport: Nanoelectronics I - Quantum Dots and Wires, Point Contacts 2

TT 11.6: Talk

Monday, March 23, 2009, 15:30–15:45, HSZ 301

Dephasing due to phonons in a double dot Aharonov-Bohm interferometer — •Björn Kubala¹, David Roosen², Florian Marquardt¹, and Walter Hofstetter² — ¹Physics Department, ASC, and CeNS, Ludwig-Maximilians-Universität, 80333 Munich, Germany — ²Institut für Theoretische Physik, Goethe-Universität, 60438 Frankfurt/Main, Germany

We investigate an Aharonov-Bohm interferometer consisting of two quantum dots coupled in parallel to two lead electrodes and to a common Einstein phonon mode. Without coupling to phonons transport of noninteracting electrons is fully coherent and the interferometer can be tuned to complete destructive interference even for finite applied bias. If phonons couple differently to the electrons on the two dots, which-path infomation is transferred to the phononic bath and the electronic coherence is diminished. It is only this dephasing due to phonons which enables transport, making the device ideal for studying decoherence issues. In this talk, we focus on results from Keldysh diagrammatic perturbation theory, which are complemented by studies using the numerical renormalization group.