منابع مشابه
Mesoscopic Josephson Effect
In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum fluctuations, and the current is also decreased by Coulomb blockade effects. We discuss the behavior of the current-voltage characteristics in a large range of...
متن کاملThree “universal” mesoscopic Josephson effects
A recent theory is reviewed for the sample-to-sample fluctuations in the critical current of a Josephson junction consisting of a disordered point contact or microbridge. The theory is based on a relation between the supercurrent and the scattering matrix in the normal state. The root-mean-square amplitude rms Ic of the critical current Ic at zero temperature is given by rms Ic ≃ e∆0/h̄, up to a...
متن کاملGe/Si nanowire mesoscopic Josephson junctions.
The controlled growth of nanowires (NWs) with dimensions comparable to the Fermi wavelengths of the charge carriers allows fundamental investigations of quantum confinement phenomena. Here, we present studies of proximity-induced superconductivity in undoped Ge/Si core/shell NW heterostructures contacted by superconducting leads. By using a top gate electrode to modulate the carrier density in ...
متن کاملac Josephson effect in the resonant tunneling through mesoscopic superconducting junctions
We investigate ac Josephson effect in the resonant tunneling through mesoscopic superconducting junctions. In the presence of microwave irradiation, we show that the trajectory of multiple Andreev reflections can be closed by emitting or absorbing photons. Consequently, photon-assisted Andreev states are formed and play the role of carrying supercurrent. On the Shapiro steps, dc component appea...
متن کاملSide-gate modulation of critical current in mesoscopic Josephson junction
We study the normal state conductance and the Josephson current in a superconductor-2DEG-superconductor structure where the size/shape of the 2DEG-region can be modified by an additional side-gate electrode. The considered transport properties follow from the retarded Green function which we compute by employing a tight-binding-like representation of the Hamiltonian in the 2DEG region. Our mode...
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ژورنال
عنوان ژورنال: Superlattices and Microstructures
سال: 1999
ISSN: 0749-6036
DOI: 10.1006/spmi.1999.0739