Related papers: Quantization of Conductance Minimum and Index Theo…
We study theoretically electronic transport through a normal metal-- superconductor (NS) interface and show that more than one conductance may be defined, depending on the pair of chemical potentials whose difference one chooses to relate…
At temperatures $T < {\hbar v_F}/{K_B d} \equiv T^{wire}$ the collective excitations are negligible and the spectrum of the short wire is dominated by the ''zero modes'' particle excitations. At temperature $ T > T^{wire}$ a spin polarized…
We consider a current-carrying, phase-coherent multi-probe conductor to which a small tunneling contact is attached. We treat the conductor and the tunneling contact as a phase-coherent entity and use a Green's function formulation of the…
The conductance of a normal-metal mesoscopic system in proximity to superconducting electrode(s) is calculated. The normal-metal part may have a general geometry, and is described as a ``circuit'' with ``leads'' and ``junctions''. The…
We investigate a normal metal -- superconductor (point) contact in the limit where the number of conducting channels in the metallic wire is reduced to few channels. As the effective Fermi energy drops below the gap energy, a conducting…
We study the transport properties of a graphene ferromagnet-insulator superconductor (FIS) junction within the Blonder-Tinkham-Klapwijk formalism by solving spin-polarized Dirac-Bogoliubov-de-Gennes equation. We find that the retro and…
We investigate quantum transport through strongly disordered barriers, made of a material with exceptionally high resistivity that behaves as an Anderson insulator or a ``bad metal'' in the bulk, by analyzing the distribution of Landauer…
Starting from exact eigenstates for a symmetric ring, we derive a low-energy effective generalized Anderson Hamiltonian which contains two spin doublets with opposite momenta and a singlet for the neutral molecule. For benzene, the singlet…
Conductance of zigzag interfaces between graphene sheet and normal metal is investigated in the tight-binding approximation. Boundary conditions, valid for a variety of scattering problems, are constructed and applied to the normal metal --…
Using spin density functional theory we study the electronic and magnetic properties of atomically thin, suspended chains containing silver and oxygen atoms in an alternating sequence. Chains longer than 4 atoms develop a half-metallic…
On the basis of the Keldysh method of non-equilibrium systems, we develop a theory of electron tunneling in normal-metal/superconductor junctions. By using the tunneling Hamiltonian model (being appropriate for the tight-binding systems),…
We measure the low bias conductance of a series of substituted benzene diamine molecules while breaking a gold point contact in a solution of the molecules. Transport through these substituted benzenes is by means of nonresonant tunneling…
We present a theoretical study of the quasiparticle and subgap conductance of generic $X/I_{sf}/S_{M}$ junction with a spin-filter barrier $I_{sf}$, where $X$ is either a normal $N$ or a ferromagnetic metal $F$ and $S_{M}$ is a…
We study the conductance of three or more semi-infinite wires which meet at a junction. The electrons in the wires are taken to interact weakly with each other through a short-range density-density interaction, and they encounter a general…
Using the integral equations of the Noncrossing Approximation, the differential conductance is computed as a function of voltage for scattering from a two channel Kondo impurity in a point contact. The results compare well to experimental…
We investigate the transport properties of a junction consisting of an electron-hole bilayer in contact with normal and superconducting leads. The electron-hole bilayer is considered as a semi-metal with two electronic bands. We assume that…
We calculate the non-linear conductance of a quantum point contact using the non-equilibrium Greens function technique within the Hartree approximation of spinless electrons. We quantitative reproduce the 0.25-anomaly in the differential…
We observe a maximum in the conductance of Aluminum / n-GaAs junctions at temperatures 20 mK lower than the superconducting transition temperature. This is the first observation of a non- monotonic behavior of the conductance near the…
The resistance is computed of an ${\rm NI}_{1}{\rm NI}_{2}{\rm S}$ junction, where N = normal metal, S = superconductor, and ${\rm I}_{i}$ = insulator or tunnel barrier (transmission probability per mode $\Gamma_{i}$). The ballistic case is…
We analyze the phase transitions of an interacting electronic system weakly coupled to free-electron leads by considering its zero-bias conductance. This is expressed in terms of two effective impurity models for the cases with and without…