https://doi.org/10.1140/epjb/e20020071
Transport theory of multiterminal hybrid structures
1
Centre de Recherches sur les Très Basses
Températures (CRTBT) (U.P.R. 5001 du CNRS,
Laboratoire conventionné avec l'Université Joseph Fourier) ,
CNRS BP 166X, 38042 Grenoble Cedex, France
2
Laboratoire d'Études des Propriétés
Électroniques des Solides,
CNRS BP 166X, 38042 Grenoble Cedex, France
Corresponding author: a melin@polycnrs-gre.fr
Received:
18
June
2001
Revised:
17
January
2002
Published online: 15 March 2002
We derive a microscopic transport theory
of multiterminal hybrid structures in which
a superconductor is connected to several
spin-polarized electrodes.
We discuss the non-perturbative
physics of extended contacts, and show that
such contacts
can be well represented by averaging out the phase
of the electronic wave function.
The intercontact Andreev reflection and elastic
cotunneling conductances are identical
if the phase can be averaged out, namely
in the
presence of at least one extended
contact.
The maximal
conductance of a two-channel contact is
proportional to
,
where D is the distance between the
contacts, a0 the lattice spacing,
is the superconducting
coherence length,
and
is the cross-over frequency
between a perturbative regime ($\omega<
\omega^*$) and
a non perturbative regime (
).
PACS: 74.80.Fp – Point contacts; SN and SNS junctions / 72.10.Bg – General formulation of transport theory
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002