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A recently demonstrated quantum electron pump is discussed within the framework of photon-assisted tunneling. Due to lack of time-reversal symmetry, different results are obtained for the pump current depending on whether or not final-state…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Mathias Wagner

We investigate the scattering of hydrogen isotopes at the W(110) surface using both classical and quantum dynamics approaches to elucidate the role of quantum effects in this system. To characterize the scattering process we focus on key…

We look at the time dependent fluctuations of the electrical charge in an open 1D quantum system represented by a quantum dot experiencing random lateral motion. In essentially non-adiabatic settings we study both diffusive and ballistic…

Chaotic Dynamics · Physics 2016-04-19 Stanislav Derevyanko , Daniel Waltner

The performance characteristics of a heat rectifier and a heat pump are studied in a non Markovian framework. The device is constructed from a molecule connected to a hot and cold reservoir. The heat baths are modelled using the stochastic…

Quantum Physics · Physics 2016-06-09 Gil Katz , Ronnie Kosloff

Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal…

Mesoscale and Nanoscale Physics · Physics 2020-09-03 Matteo Carrega , Alba Crescente , Dario Ferraro , Maura Sassetti

We present a realization of quantized charge pumping. A lateral quantum dot is defined by metallic split gates in a GaAs/AlGaAs heterostructure. A surface acoustic wave whose wavelength is twice the dot length is used to pump single…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. Ebbecke , N. E. Fletcher , T. J. B. M. Janssen , F. J. Ahlers , M. Pepper , H. E. Beere , D. A. Ritchie

Spin distribution in the diffraction pattern of two-dimensional electron gas by a split gate and a quantum point contact is computed in the presence of the spin-orbit coupling. After diffracted, the component of spin perpendicular to the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Cheng-Ju Lin , Chyh-Hong Chern

We consider the full driven quantum dynamics of a qubit realized as spin of electron in a one-dimensional double quantum dot with spin-orbit coupling. The driving perturbation is taken in the form of a single half-period pulse of electric…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 D. V. Khomitsky , E. Ya. Sherman

We have developed a general theory for a parametric pump consisting of a nonmagnetic system with two ferromagnetic leads whose magnetic moments orient at an angle $\theta$ with respect to each other. In this theory, the leads can maintain…

Condensed Matter · Physics 2007-05-23 Wu Junling , Baigeng Wang , Jian Wang

We study the time-development processes of spin and charge transport phenomena in a topological Dirac semimetal attached to a ferromagnetic insulator with a precessing magnetization. Compared to conventional normal metals, topological Dirac…

Materials Science · Physics 2020-01-01 Takahiro Misawa , Kentaro Nomura

Magnetic phase transitions between ordered phases are often understood on the basis of semi-classical spin models. Deviations from the classical description due to the quantum nature of the atomic spins as well as quantum fluctuations are…

Strongly Correlated Electrons · Physics 2026-05-19 Tobias Dannegger , Imre Hagymási , Levente Rózsa , Ulrich Nowak

We study adiabatic pumping through a two-level quantum dot with spin-orbit coupling. Using a diagrammatic real-time approach, we calculate both the pumped charge and spin for a periodic variation of the dot's energy levels in the limit of…

Mesoscale and Nanoscale Physics · Physics 2013-02-11 Stephan Rojek , Jürgen König , Alexander Shnirman

Spin pumping effect is a sensitive and well-established experimental method in two-dimensional (2D) magnetic materials. We propose that spin pumping effect can be a valuable probe for non-Fermi liquid (NFL) behaviors at the 2D interface of…

Strongly Correlated Electrons · Physics 2025-03-19 Xiao-Tian Zhang , Yi-Hui Xing , Xu-Ping Yao , Yuya Ominato , Long Zhang , Mamoru Matsuo

We investigate the photon pumping effect in a topological model consisting of a periodically driven spin-1/2 coupled to a quantum cavity mode out of the adiabatic limit. In the strong-drive adiabatic limit, a quantized frequency conversion…

Mesoscale and Nanoscale Physics · Physics 2022-01-05 Christina Psaroudaki , Gil Refael

We consider a quantum particle in a waveguide which consists of an infinite straight Dirichlet strip divided by a thin semitransparent barrier on a line parallel to the walls which is modeled by a $\delta$ potential. We show that if the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. Exner , D. Krejcirik

We study the pump current and noise properties in an adiabatically modulated magnetic nanowire with double domain walls (DW). The modulation is brought about by applying a slowly oscillating magnetic and electric fields with a controllable…

Mesoscale and Nanoscale Physics · Physics 2016-09-08 Rui Zhu , Jamal Berakdar

We study particle and spin transport in a single mode quantum point contact using a charge neutral, quantum degenerate Fermi gas with tunable, attractive interactions. This yields the spin and particle conductance of the point contact as a…

We propose a new type of quantum pump made out of graphene, adiabatically driven by oscillating voltages applied to two back gates. From a practical point of view, graphene-based quantum pumps present advantages as compared to normal pumps,…

Materials Science · Physics 2011-07-18 Elsa Prada , Pablo San-Jose , Henning Schomerus

Single-charge tunneling is a decoherence mechanism affecting superconducting qubits, yet the origin of excess quasiparticle excitations (QPs) responsible for this tunneling in superconducting devices is not fully understood. We measure the…

We present some conjectured approximations for spin expectations in a Quantum Heisenberg system. The conjectures are based on numerical experimentation, some theoretical insights and underpinning, and aesthetic value. We hope theoretical…

Mathematical Physics · Physics 2007-05-23 Paul Federbush