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Related papers: Quantum Dot as Spin Filter and Spin Memory

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It is shown that, for appropriate values of electron energy, the silicene dot can work as a controllable spin polarizer. The spin polarizer can polarize the spin of transmitted electrons from nearly pure down to nearly pure up by changing…

Mesoscale and Nanoscale Physics · Physics 2015-01-19 Hamidreza Simchi , Mahdi Esmaeilzadeh , Hossein Mazidabadi , Mohammad Norouzi

Spin effects in the transport properties of a quantum dot with spin-charge separation are investigated. It is found that the non-linear transport spectra are dominated by spin dynamics. Strong spin polarization effects are observed in a…

Strongly Correlated Electrons · Physics 2007-05-23 Alessandro Braggio , Maura Sassetti , Bernhard Kramer

We study theoretically spin transport through a single-molecule magnet (SMM) in the sequential and cotunneling regimes, where the SMM is weakly coupled to one ferromagnetic and one normalmetallic leads. By a master-equation approach, it is…

Mesoscale and Nanoscale Physics · Physics 2017-09-19 Haiqing Xie , Fuming Xu , Hujun Jiao , Qiang Wang , J. -Q. Liang

We study a two-electron quantum dot molecule in a magnetic field by the direct diagonalization of the Hamiltonian matrix. The ground states of the molecule with the total spin S=0 and S=1 provide a possible realization for a qubit of a…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 A. Harju , S. Siljamäki , R. M. Nieminen

A quantum computer based on an asymmetric coupled dot system has been proposed and shown to operate as the controlled-NOT-gate. The basic idea is (1) the electron is localized in one of the asymmetric coupled dots. (2)The electron transfer…

Quantum Physics · Physics 2008-12-18 Tetsufumi Tanamoto

We study an influence of a finite magnetic field on a small spin-degenerate quantum dot with even number of electrons, attached to metallic leads. It is shown that, under certain conditions, the low energy physics of the system can be…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. Pustilnik , Y. Avishai , K. Kikoin

We propose an idea for probing spin states of two coupled quantum dots (CQD), by the dc Josephson current flowing through them. This theory requires weak coupling between CQD and electrodes, but allows arbitrary inter-dot tunnel coupling,…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu Zhu , Qing-feng Sun , Tsung-han Lin

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

We exploit the pumped spin-current and current noise spectra under equilibrium condition in a single quantum dot connected to two normal leads, as an electrical scheme for detection of the electron spin resonance (ESR) and decoherence. We…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Bing Dong , H. L. Cui , X. L. Lei

We theoretically show that intriguing features of coherent many-body physics can be observed in electron transport through a quantum dot (QD). We first derive a master equation based framework for electron transport in the Coulomb-blockade…

Mesoscale and Nanoscale Physics · Physics 2012-09-03 Martin J. A. Schuetz , Eric M. Kessler , J. Ignacio Cirac , Geza Giedke

We present a stochastic thermodynamics analysis of an electron-spin-resonance pumped quantum dot device in the Coulomb-blocked regime, where a pure spin current is generated without an accompanying net charge current. Based on a generalized…

Statistical Mechanics · Physics 2020-03-18 JunYan Luo , Yiying Yan , Hailong Wang , Jing Hu , Xiao-Ling He , Gernot Schaller

We introduce a new spin filter based on spin-resolved Fano resonances due to spin-split levels in a quantum ring (QR) side-coupled to a quantum wire (QW). Spin-orbit coupling inside the QR, together with external magnetic fields, induces…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Minchul Lee , C. Bruder

We investigate a silicon single-electron transistor (SET) in a metal-oxide-semiconductor (MOS) structure by applying a magnetic field perpendicular to the sample surface. The quantum dot is defined electrostatically in a point contact…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Binhui Hu , C. H. Yang

By measuring electron tunneling between a ferromagnet and individual energy levels in an aluminum quantum dot, we show how spin-resolved quantum states can be used as filters to determine spin-dependent tunneling rates. We also observe…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Mandar M. Deshmukh , D. C. Ralph

We propose a quantum processor based upon single-molecule magnets and spin transfer torque described by PT-symmetric quantum mechanics. In recent years PT-symmetric Hamiltonians have been used to obtain stability thresholds of various…

Mesoscale and Nanoscale Physics · Physics 2019-05-22 Aleix Bou Comas , Eugene M. Chudnovsky , Javier Tejada

We evaluate the spin density oscillations arising in quantum spin Hall quantum dots created via two localized magnetic barriers. The combined presence of magnetic barriers and spin-momentum locking, the hallmark of topological insulators,…

Mesoscale and Nanoscale Physics · Physics 2013-06-24 Giacomo Dolcetto , Niccolò Traverso Ziani , Matteo Biggio , Fabio Cavaliere , Maura Sassetti

Quantum rings connected to ballistic circuits couple strongly to external magnetic fields if the connection is not symmetric. By analytical theory and computer simulation I show that properly connected rings can be used to pump currents in…

Mesoscale and Nanoscale Physics · Physics 2014-07-24 Michele Cini

We use the spin-polarized excitons in a single quantum dot to design optical controls for basic operations in quantum computing. We examine the ultrafast nonlinear optical processes required and use the coherent nonlinear optical responses…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Pochung Chen , C. Piermarocchi , L. J. Sham

A correct general formula for the spin current through an interacting quantum dot coupled to ferromagnetic leads with magnetization at an arbitrary angle $\theta$ is derived within the framework of the Keldysh formalism. Under asymmetric…

Mesoscale and Nanoscale Physics · Physics 2009-03-18 Hao Zhang , Guang-Ming Zhang , Lu Yu

A scheme of spin diode is proposed that uses a step-like quantum wire with Rashba spin-orbit interaction, connected to two leads with different width. It is shown that a very large vertical spin-polarized current can be generated when…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Xianbo Xiao , Yuguang Chen