2009/01/09 by A M Lunde, A. M. Lunde, A De Martino +7 · 2 citations
Engineering · Physics and Astronomy · #Interaction point #Molecular Junctions and Nanostructures #Point (geometry) #Quantum #Quantum and electron transport phenomena #Quantum dot #Quantum fluctuation #Semiconductor Quantum Structures and Devices #Work (physics) #cond-mat.mes-hall
paper · pdf · doi:10.1088/1367-2630/11/2/023031
published as New J. Phys. 11, 023031 (2009) · 29 pages, New Journal of Physics, in press
arxiv created 2009/01/09 · openalex publication_date 2009/02/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider electron–electron interaction effects in quantum point contacts on the first quantization plateau, taking into account all scattering processes. We compute the low-temperature linear and nonlinear conductance, shot noise and thermopower, by perturbation theory and a self-consistent nonperturbative method. On the conductance plateau, the low-temperature corrections are solely due to momentum-nonconserving processes that change the relative number of left- and right-moving electrons. This leads to a suppression of the conductance for increasing temperature or voltage. The size of the suppression is estimated for a realistic saddle-point potential, and is largest in the beginning of the conductance plateau. For large magnetic field, interaction effects are strongly suppressed by the Pauli principle, and hence the first spin-split conductance plateau has a much weaker interaction correction. For the nonperturbative calculations, we use a self-consistent nonequilibrium Green's function approach, which suggests that the conductance saturates at elevated temperatures. These results are consistent with many experimental observations related to the so-called 0.7 anomaly.