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We investigate the non-equilibrium charge and spin-dependent currents in a quantum ring with a Rashba spin orbit interaction (SOI) driven by two asymmetric picosecond electromagnetic pulses. The equilibrium persistent charge and persistent…

Mesoscale and Nanoscale Physics · Physics 2009-12-01 Zhen-Gang Zhu , Jamal Berakdar

A formula of the spin current in mesoscopic superconductors is derived from the mean-field theory of superconductivity. The spin flow is generated by the spatial fluctuations of $\vec{d}$ which represents a spin state of spin-triplet…

Superconductivity · Physics 2009-11-11 Y. Asano

A great endeavor has been undertaken to engineer molecular rotors operated by an electrical current. A frequently met operation principle is the transfer of angular momentum taken from the incident flux. In this paper we present an…

Mesoscale and Nanoscale Physics · Physics 2022-12-12 Richard Korytár , Ferdinand Evers

Coherent resonant tunneling through an artificial molecule of quantum dots in an inhomogeneous magnetic field is investigated using an extended Hubbard model. Both the multiterminal conductance of an array of quantum dots and the persistent…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. A. Stafford , R. Kotlyar , S. Das Sarma

Current induced switching in Co/Cu/Co trilayers is described in terms of ab-initio determined magnetic twisting energies and corresponding sheet resistances. In viewing the twisting energy as an energy flux the characteristic time thereof…

Materials Science · Physics 2009-11-10 P. Weinberger , A. Vernes , B. L. Gyorffy , L. Szunyogh

We argue that the process of constructing the quantum mechanical current of the Pauli equation by copying the line of arguments used in the spin-0 case, i.e. the Schr\"{o}dinger equation, is ambiguous. We show that a non-relativistic…

Physics Education · Physics 2009-10-31 Marek Nowakowski

The zero bias conductance of quantum dots coupled to ferromagnetic leads is investigated. In the strong coupling regime, it is found that the conductance is a non-monotonic function of the angle between the magnetisation directions in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. Fransson

Transient and steady state currents through dc-biased quantum impurity models beyond the linear response regime are of considerable interest, both from an experimental and a theoretical point of view. Here we present a new analytical…

Strongly Correlated Electrons · Physics 2013-05-29 Pei Wang , Stefan Kehrein

I consider the quantum interference of electrons moving along knotted trajectories under external magnetic field. The induced persistent current is formulated in terms of characteristic parameters that classify the torus knot geometry. The…

Quantum Physics · Physics 2015-06-04 Hiroyuki Shima

We show how to exploit algebraic relations of operators (or matrices) which constitute the non-equilibrium matrix product steady state of a boundary driven quantum spin chain to find partial differential equations determining all the…

Statistical Mechanics · Physics 2016-08-08 Berislav Buca , Tomaz Prosen

We study the time-dependent transport of charge and spin through a ring-shaped region sequentially coupled to a weakly interacting quantum dot in the presence of an Aharonov-Bohm flux and spin-orbit interaction. The time-dependent…

Mesoscale and Nanoscale Physics · Physics 2009-01-09 F. Romeo , R. Citro , M. Marinaro

We extend the standard solid-state quantum mechanical Hamiltonian containing only Coulomb interactions between the charged particles by inclusion of $1/c^2$ terms representing (transverse) current-current interaction. For its derivation we…

Quantum Physics · Physics 2019-06-27 Ladislaus Alexander Bányai

The quantized current generated by a quantum dot pump is calculated numerically. The numerical simulation is done by dividing the time varying potential into many static potentials with a short time interval and calculating the electron…

Mesoscale and Nanoscale Physics · Physics 2018-01-16 Ye-Hwan Ahn , Yunchul Chung

Resonant tunneling of electrons between two ferromagnets and a quantum dot in the presence of an externally applied magnetic field reveals a strong gate dependence in the linear and nonlinear bias regime. This gate dependence originates…

Mesoscale and Nanoscale Physics · Physics 2020-07-08 S. Mundinar , A. Hucht , J. König , S. Weiss

Using suitable magnetic flux operators established in terms of discrete derivatives leads to quantum-mechanical descriptions of LC-circuits with an external time dependent periodic voltage. This leads to second order discrete Schrodinger…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 C. Micu , E. Papp , L. Aur

We investigate the parametric pumping of a hybrid structure consisting of a normal quantum dot, a normal lead and a superconducting lead. Using the time dependent scattering matrix theory, we have derived a general expression for the pumped…

Condensed Matter · Physics 2009-11-07 Baigeng Wang , Jian Wang

Spin and charge currents can be generated by an ac voltage through a one-channel quantum wire with strong electron interactions in a static uniform magnetic field. In a certain range of low voltages, the spin current can grow as a negative…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Bernd Braunecker , D. E. Feldman

We consider the magnetostatic response to an external magnetic field of a crystal containing off-center ions, such as Li^+ in KCl and KBr or the apical oxygens O(A) in the LaSCO family of layered perovskites. Magnetic dipoles are deduced…

Materials Science · Physics 2007-05-23 Mladen Georgiev

Using the self-consistent Hartree-Fock approximation for spinless electrons at zero temperature, we study the persistent current of the interacting electron gas in a one-dimensional continuous ring containing a single $\delta$ barrier. We…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Radoslav Nemeth , Martin Mosko

We discuss the possibility to generate, manipulate, and probe single spins in single-level quantum dots coupled to ferromagnetic leads. The spin-polarized currents flowing between dot and leads lead to a non-equilibrium spin accumulation,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Matthias Braun , Jürgen König , Jan Martinek