The phase-dependent linear conductance of a superconducting quantum point contact

Abstract

Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in:Journal of Physics Condensed Matter 8. 4 (1996) AbstractThe exact expression for the phase-dependent linear conductance of a weakly damped superconducting quantum point contact is obtained. The calculation is performed by summing up the complete perturbative series in the coupling between the electrodes. The failure of any finite order perturbative expansion in the limit of small voltage and small quasi-particle damping is analyzed in detail. In the low transmission regime this nonperturbative calculation yields a result which is at variance with standard tunnel theory. Our result predicts the correct sign of the quasi-particle pair interference term and exhibits an unusual phase-dependence at low temperatures in qualitative agreement with the available experimental data.PACS numbers: 74.50.+r, 85.25.Cp, 73.20.Dx Since the early stages in the theory of Josephson junctions it has been customary to write the total current through the junction aswhere the total superconducting phase difference between the electrodes is related to the applied bias voltage by dφ/dτ = 2eV /h = ω 0 .

Photon-assisted Andreev tunneling through a mesoscopic hybrid system

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“…To simplify the discussion, in the following we only consider the harmonic external field, i.e., W ␤ (t)ϭW ␤ cos t (␤ϭL,d). 1,2 Introducing the notation G mn (⑀)ϵG nϪm (⑀ϩm), 23 ͓here and in Eq. ͑20͒, G can be g r , ⌺ R r , etc.͔ noticing that different components G mn are related by G mn (⑀)ϭG 0,nϪm (⑀ϩm), then the Fourier transformation of the Green's function g r (t,tЈ) and the self-energy ⌺ r (t,tЈ) are easily obtained…”

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Resonant Andreev reflection in a normal-metal–quantum-dot–superconductor system

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A Simple Perturbation Theory of a Quantum Dot Coupled to Superconducting Leads

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