Universal properties of mesoscopic fluctuations of the secondary gap in superconducting proximity systems

The energy levels of a quasicontinuous spectrum in mesoscopic systems fluctuate in positions and the distribution of the fluctuations reveals information about the microscopic nature of the structure under consideration. Here, we investigate mesoscopic fluctuations of a secondary gap that appears in the quasiclassical spectrum of a chaotic...

Order, disorder, and tunable gaps in the spectrum of Andreev bound states in a multiterminal superconducting device

We consider the spectrum of Andreev bound states (ABSs) in an exemplary four-terminal superconducting structure where four chaotic cavities are connected by quantum point contacts to the terminals and to each other forming a ring. We nickname the resulting device 4T-ring. Such a tunable device can be realized in a 2D electron gas...

Secondary “smile”-gap in the density of states of a diffusive Josephson junction for a wide range of contact types

The superconducting proximity effect leads to strong modifications of the local density of states in diffusive or chaotic cavity Josephson junctions, which displays a phase-dependent energy gap around the Fermi energy. The so-called minigap of the order of the Thouless energy ETh is related to the inverse dwell time in the diffusive region in...

“Smile” Gap in the Density of States of a Cavity between Superconductors

The density of Andreev levels in a normal metal (N) in contact with two superconductors (S) is known to exhibit an induced minigap related to the inverse dwell time. We predict a small secondary gap just below the superconducting gap edge—a feature that has been overlooked so far in numerous microscopic studies of the density of states in S?N?S...

Spin-dependent boundary conditions for isotropic superconducting Green’s functions

The quasiclassical theory of superconductivity provides the most successful description of diffusive heterostructures comprising superconducting elements, namely, the Usadel equations for isotropic Green’s functions. Since the quasiclassical and isotropic approximations break down close to interfaces, the Usadel equations have to be supplemented...

Elementary charge-transfer processes in mesoscopic conductors

We determine charge-transfer statistics in a quantum conductor driven by a time-dependent voltage and identify the elementary transport processes. At zero temperature unidirectional and bidirectional single-charge transfers occur. The unidirectional processes involve electrons injected from the source terminal due to excess dc bias voltage. The...

Elementary Events of Electron Transfer in a Voltage-Driven Quantum Point Contact

Overscreening diamagnetism in cylindrical superconductor-normal metal-heterostructures

Andreev Reflection Eigenvalue Density in Mesoscopic Conductors

Negative magnetoresistance in Andreev interferometers

Absolute spin-valve effect with superconducting proximity structures

Superconducting proximity effect in clean ferromagnetic layers

Full counting statistics of electron transfer between superconductors

Oscillations of Andreev states in clean ferromagnetic films

Full current statistics in diffusive normal-superconductor structures

Spin-accumulation and Andreev-reflection in a mesoscopic ferromagnetic wire

The electron transport though ferromagnetic metal-superconducting hybrid devices is considered in the non-equilibrium Green's function formalism in the quasiclassical approximation. Attention if focused on the limit in which the exchange splitting in the ferromagnet is much larger than the superconducting energy gap. Transport properties are...

Spin accumulation and Andreev reflection in a mesoscopic ferromagnetic wire