Multiple Particle Scattering in Quantum Point Contacts
arXiv:cond-mat/0508752 · doi:10.1103/PhysRevB.72.121312
Abstract
Recent experiments performed on weakly pinched quantum point contacts, have shown a resistance that tend to decrease at low source drain voltage. We show that enhanced Coulomb interactions, prompt by the presence of the point contact, may lead to anomalously large multiple-particle scattering at finite bias voltage. These processes tend to decrease at low voltage, and thus may account for the observed reduction of the resistance. We concentrate on the case of a normal point contact, and model it by a spinfull interacting Tomonaga-Luttinger liquid, with a single impurity, connected to non interacting leads. We find that sufficiently strong Coulomb interactions enhance two-electron scattering, so as these dominate the conductance. Our calculation shows that the effective charge, probed by the shot noise of such a system, approaches a value proportional to e* = 2e at sufficiently large backscattering current. This distinctive hallmark may be tested experimentally. We discuss possible applications of this model to experiments conducted on Hall bars.
5 pages, 2 figures
References in corpus (5)
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- Kondo model for the "0.7 anomaly" in transport through a quantum point contact
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Cited by in corpus (12)
- Topological insulators and superconductors
- Kondo effect in the helical edge liquid of the quantum spin Hall state
- Fractional Shot Noise in the Kondo Regime
- Transport properties of partially equilibrated quantum wires
- Electron-electron interaction effects in quantum point contacts
- Electrical control of the Kondo effect in a helical edge liquid
- Resistivity of inhomogeneous quantum wires
- Transport in partially equilibrated inhomogeneous quantum wires
- Equilibration of Luttinger liquid and conductance of quantum wires
- Electron-electron scattering and magnetoresistance of ballistic microcontacts
- Electronic transport in inhomogeneous quantum wires
- Tunable 0.7 conductance plateau in quantum dots