相关论文: Parity Effect in a mesoscopic superconducting ring
In the present article we perform analytical and numerical calculations related to persistent currents in 2D isolated mesoscopic annular cavities threaded by a magnetic flux. The system considered has a high number of open channels and…
Quantum mechanics predicts that the equilibrium state of a resistive electrical circuit contains a dissipationless current. This persistent current has been the focus of considerable theoretical and experimental work, but its basic…
We investigate the ground state current of an isolated hybrid normal/superconducting ring (NS ring), threaded by an Aharonov-Bohm magnetic flux. We calculate the excitation spectrum of the ring for any values of the lengths of the normal…
It was experimentally found that quantum magnetoresistive hc/2e periodic oscillations of the Little-Parks type in a superconducting mesoscopic ring with decreasing temperature and increasing applied dc current are modified to the sum of…
We consider the mesoscopic normal persistent current (PC) in a very low-temperature superconductor with a bare transition temperature $T_c^0$ much smaller than the Thouless energy $E_c$. We show that in a rather broad range of pair-breaking…
We investigate superconductivity in a grand canonical ensemble with {\it fixed number parity} (even or odd). In the low temperature limit we find small corrections to the BCS gap equation and energy spectrum $E(k)$. The even-odd free energy…
We analyze the charge transport through a single level quantum dot coupled to a normal (N) and superconducting (S) leads where the electron pairs exist either as the coherent (for temperatures below T_c) or incoherent objects (in a region…
It is well-known that some physical effects may arise in the spacetime of a straigth cosmic string due to its global conic properties. Among these effects, the vacuum polarization effect has been extensively studied in the litterature. In…
Using the properties of the transfer matrix of one-dimensional quantum mechanical systems, we derive a technique to exactly compute the persistent current across a hybrid normal-superconducting-mesoscopic ring pierced by a magnetic flux Phi…
We thoroughly study the persistent current of noninteracting electrons in one, two, and three dimensional thin rings. We find that the results for noninteracting electrons are more relevant for individual mesoscopic rings than hitherto…
The transfer of charge between different regions of a phase-coherent mesoscopic sample is investigated. Charge transfer from a side branch quantum dot into a ring changes the persistent current through a sequence of plateaus of diamagnetic…
The effect of point defects on persistent currents in mesoscopic systems is studied in a simple tight-binding model. Using an analogy with the treatment of the critical quantum Ising chain with defects, conformal invariance techniques are…
We study the Little-Parks effect for mesoscopic loops with very nonuniform thickness. The results follow the trend of the phase diagram obtained for almost uniform thickness. In particular, the singly-connected state is stable on a line…
We study anomalous mesoscopic transport effects at the onset of the superconducting transition focusing on the observed large Nernst-Ettinghausen signal in disordered thin films. In the vicinity of the transition, as the Ginzburg-Landau…
We analyse the periodicity of persistent currents in quantum spin Hall loops, partly covered with an $s$-wave superconductor, in the presence of a flux tube. Much like in normal (non-helical) metals, the periodicity of the single-particle…
Consistent with the predictions of Kibble and Zurek, scaling behaviour has been seen in the production of fluxoids during temperature quenches of superconducting rings. However, deviations from the canonical behaviour arise because of…
Fluctuations of the amplitude of the order parameter govern the properties of superconducting systems close to the critical transition temperature. In the BCS regime we examine the contribution of these pairing fluctuations to the…
Superconductors used in magnet technology could carry extreme currents because of their ability to keep the magnetic flux motionless. The dynamics of the magnetic flux interaction with superconductors is controlled by this property. The…
We present a new method for computing the wave function in the presence of constraints. As an explicit example we compute the wave function for the many electrons problem in coupled metallic rings in the presence of external magnetic…
Using selection rules imposed by the Pauli principle, we classify pairing correlations according to their symmetry properties with respect to spin, momentum, and energy. We observe that inhomogeneity always leads to mixing of even- and…