2003/03/19 by Florian Marquardt, C. Bruder
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.68.195305
published as Phys. Rev. B 68, 195305 (2003). · 18 pages, 8 figures; For a tutorial introduction to dephasing see http://iff.physik.unibas.ch/~florian/dephasing/dephasing.html
arxiv created 2003/03/19 · arxiv updated 2009/11/30
We analyze dephasing in a model system where electrons tunnel sequentially through a symmetric interference setup consisting of two single-level quantum dots. Depending on the phase difference between the two tunneling paths, this may result in perfect destructive interference. However, if the dots are coupled to a bath, it may act as a which-way detector, leading to partial suppression of the phase-coherence and the reappearance of a finite tunneling current. In our approach, the tunneling is treated in leading order whereas coupling to the bath is kept to all orders (using P(E) theory). We discuss the influence of different bath spectra on the visibility of the interference pattern, including the distinction between "mere renormalization effects" and "true dephasing".