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TT: Fachverband Tiefe Temperaturen

TT 22: Quantum Dots, Quantum Wires, Point Contacts

TT 22.5: Vortrag

Dienstag, 17. März 2020, 10:30–10:45, HSZ 201

Interference and shot noise in a degenerate Anderson-Holstein model — Michael Niklas, •Andrea Donarini, and MIlena Grifoni — Institut für Theoretische Physik, Universität Regensburg, Germany

Mechanical degrees of freedom can leave clear signatures in the transport characteristics of a nanojunction. We study an Anderson-Holstein model with orbital degeneracies [1] and tunnelling phases that allow for the formation of dark states [2]. The resulting destructive interference yields a characteristic pattern of positive and negative differential conductance features with enhanced shot noise, without further asymmetry requirements in the coupling to the leads. Measurements on suspended carbon nanotubes showed analogous effects [3,4], which acquire in this framework a new interpretation, free of ad-hoc matching of vibrational and electronic energies. The Lamb-shift renormalization introduced by charge fluctuations is the key ingredient for the understanding of such transport characteristics.

[1] M. G. Schultz, Phys. Rev. B 82, 155408 (2010)

[2] A. Donarini et al., Nature Comm. 10, 381 (2019)

[3] S. Sapmaz et al., Phys. Rev. Lett. 96, 026801 (2006)

[4] R. Leturcq et al., Nat. Phys. 5, 327 (2009)