相关论文: Persistent current in a ring coupled to an externa…

Two infinite, two-dimensional, lattice, free fermion systems, initially in different invariant states, are allowed to communicate via two point contacts, through which direct tunneling of fermions takes place. Calculations of the local…

In equilibrium, the number of conduction electrons in a solid substance depends on the conformation of the atoms in the substance. When a magnetic field is applied, it takes time for the system to come to a new equilibrium with a new…

The remarkably large persistent currents that are observed in disordered micron-scale gold rings at low temperatures have recently been explained in a theory of non-interacting electrons scattered by crystal grain boundaries. The present…

Persistent currents circulate continuously without requiring external power sources. Here, we extend their theory to include dissipation within the framework of non-Hermitian quantum Hamiltonians. Using Green's function formalism, we…

We discuss the phase coherence properties of a mesoscopic normal ring coupled to an electric environment via Coulomb interactions. This system can be mapped onto the Caldeira-Leggett model with a flux dependent tunneling amplitude. We show…

We study effects of local electron interactions on the persistent current of one dimensional disordered rings. For different realizations of disorder we compute the current as a function of Aharonov-Bohm flux to zeroth and first orders in…

We analyze the effect of Rashba spin-orbit coupling and of a local tunnel barrier on the persistent spin and charge currents in a one-dimensional conducting Aharonov-Bohm (AB) ring symmetrically coupled to two leads. First, as an important…

We study the effect of a strong electron-electron (e-e) interaction in a system of two concentric one-dimensional rings with incommensurate areas A_1 and A_2, coupled by a tunnel amplitude. For noninteracting particles the magnetic moment…

The generation of entanglement between two oscillators that interact via a common reservoir is theoretically studied. The reservoir is modeled by a one-dimensional harmonic crystal initially in thermal equilibrium. Starting from a separable…

Tunneling, though a physical reality, is shrouded in mystery. Wave packets cannot be constructed under the barrier and group velocity cannot be defined. The tunneling particle can be observed on either sides of the barrier but its…

We demonstrate that persistent current in meso- and nanorings may fluctuate down to zero temperature provided the current operator does not commute with the total Hamiltonian of the system. For a model of a quantum particle on a ring we…

Ultracold atomic systems have emerged as strong contenders amongst the various quantum systems relevant for developing and implementing quantum technologies due to their enhanced control and flexibility of the operating conditions. In this…

Spin transport typically relies on direct manipulation of the spin degree of freedom via magnetic fields, spin-orbit coupling, or engineered spin-dependent potentials. We show theoretically that directional spin currents can arise in a…

We examine bosonic atoms that are confined in a toroidal, quasi-one-dimensional trap, subjected to a random potential. The resulting inhomogeneous atomic density is smoothened for sufficiently strong, repulsive interatomic interactions.…

We investigate persistent charge and spin currents in a magnetic quantum ring threaded by an Aharonov-Bohm flux, in the presence of a side-coupled one-dimensional non-magnetic chain. The neighboring magnetic moments in the ring are arranged…

The quantum theory for mesoscopic electric circuit is briefly described. The uncertainty relation for electric charge and current modifies the tranditional Heisenberg uncertainty relation. The mesoscopic ring is regarded as a pure L-design,…

The stability of persistent currents in a two-component Bose-Einstein condensate in a toroidal trap is studied both in the miscible and immiscible regimes. In the miscible regime we show that superflow decay is related to linear…

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…

Theoretical approaches to one-dimensional and quasi-one-dimensional quantum rings with a few electrons are reviewed. Discrete Hubbard-type models and continuum models are shown to give similar results governed by the special features of the…

We propose four different mechanisms responsible for paramagnetic or diamagnetic persistent currents in normal metal rings and determine the circumstances for change of the current from paramagnetic to diamagnetic ones and {\it vice versa}.…