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Related papers: Non-stationary spin-filtering effects in correlate…

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In this contribution, we start off from a fully relativistic description of a single electron non-minimally coupled to an external electromagnetic field. Making direct use of the field equation, instead of canonically deriving from the…

Mesoscale and Nanoscale Physics · Physics 2020-02-24 Rodrigo Turcati , Carlos Andres Bonilla Quintero , José Abdalla Helayël-Neto , Enrique Arias

Few-electron systems confined in a quantum dot laterally coupled to a surrounding quantum ring in the presence of an external magnetic field are studied by exact diagonalization. The distribution of electrons between the dot and the ring is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Szafran , F. M. Peeters , S. Bednarek

Due to the spin-orbital coupling in a semiconductor quantum dot, a freely precessing electron spin produces a time-dependent charge density. This creates a sizeable electric field outside the dot, leading to promising applications in…

Mesoscale and Nanoscale Physics · Physics 2008-04-12 L. S. Levitov , E. I. Rashba

We consider interaction effects related to a nonuniform magnetization in ferromagnetic nanowires and their possible generalization to nanorings. First we show that the electric current in a ferromagnetic nanowire with more than one domain…

Mesoscale and Nanoscale Physics · Physics 2011-11-17 Nicholas Sedlmayr , Vitalii Dugaev , Jamal Berakdar

We propose that a magnetic quantum wire composed of magnetic and non-magnetic atomic sites can be used as a spin filter for a wide range of applied bias voltage. We adopt a simple tight-binding Hamiltonian to describe the model where the…

Mesoscale and Nanoscale Physics · Physics 2010-03-15 Moumita Dey , Santanu K. Maiti , S. N. Karmakar

We propose a nanoscale device consisting of a double quantum dot with a full exchange and pair hopping interaction. In this design, the current can only flow through the upper dot, but is sensitive to the spin state of the lower dot. The…

Mesoscale and Nanoscale Physics · Physics 2025-02-25 Pierre Lombardo , Imam Makhfudz , Steffen Schäfer , Roland Hayn

The spin dynamics in a broad range of systems can be studied using circularly polarized optical excitation with alternating helicity. The dependence of spin polarization on the frequency of helicity alternation, known as the spin inertia…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 E. A. Zhukov , E. Kirstein , D. S. Smirnov , D. R. Yakovlev , M. M. Glazov , D. Reuter , A. D. Wieck , M. Bayer , A. Greilich

The spin-orbit coupling influences the total spin of semiconductor quantum dots. We analyze the theoretical prediction for the combined effects of spin-orbit coupling, weak vertical magnetic fields and deformation of the dot. Our results…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Manuel Valin-Rodriguez , Antonio Puente , Llorens Serra , Enrico Lipparini

We present studies of the Coulomb blockade and Kondo regimes of transport through a quantum dot connected to current leads through spin-polarizing quantum point contacts (QPCs). This structure, arising from the effect of lateral spin-orbit…

Strongly Correlated Electrons · Physics 2010-12-21 Anh T. Ngo , Edson Vernek , Sergio E. Ulloa

We propose a device acting as a spin valve which is based on a double quantum dot structure with parallel topology. Using the exact analytical solution for the noninteracting case we argue that, at a certain constellation of system…

Mesoscale and Nanoscale Physics · Physics 2010-03-18 J. P. Dahlhaus , S. Maier , A. Komnik

We have studied the current through a carbon nanotube quantum dot with one ferromagnetic and one normal-metal lead. For the values of gate voltage at which the normal lead is resonant with the single available non-degenerate energy level on…

Mesoscale and Nanoscale Physics · Physics 2008-08-20 Christopher A. Merchant , Nina Markovic

We develop a theoretical description of transport through quantum dots connected to reservoirs via spin-polarized ballistic contacts. Rate equations account for spin accumulation inside the dot, electron-electron interactions, and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Eugene G. Mishchenko , Arne Brataas , Yaroslav Tserkovnyak

We show theoretically that a strongly spin-polarized current can be generated in semiconductors by taking advantage of the ferromagnetic phase of a quantum dot array (QDA). A Hubbard model with coupling to leads is used to study the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 David M. -T. Kuo , Y. -C. Chang

We examine and identify magnetoresistance mechanisms in 2D system containing a sizable concentration of magnetic ions. We argue that some of these mechanisms can serve as a tool to measure spin polarization. Lack of spin degeneracy and…

The effect of electric field, applied on systems in the nanoscale regime has attracted a lot of research in recent times. We highlight some of the recent results in the field of single molecule electronics and then move on to focus on some…

Materials Science · Physics 2008-10-11 S. Lakshmi , Sudipta Dutta , Swapan K. Pati

We analyze the effects of spin-orbit coupling on fluctuations of the conductance of a quantum dot fabricated in a GaAs heterostructure. We argue that spin-orbit effects may become important in the presence of a large parallel magnetic field…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 B. I. Halperin , Ady Stern , Y. Oreg , J. H. Cremers , J. Folk , C. M. Marcus

Quantum interference in Aharonov-Bohm (AB) ring structure provides additional control of spin at mesoscopic scale. We propose a scheme for spin filter by studying the coherent transport through the AB structure with lateral magnetic…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. W. Wu , J. Zhou , Q. W. Shi

A novel spin filtering in two-dimensional electron system with nonuniform spin-orbit interactions (SOI) is theoretically studied. The strength of SOI is modulated perpendicular to the charge current. A spatial gradient of effective magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Jun-ichiro Ohe , Masayuki Yamamoto , Tomi Ohtsuki , Junsaku Nitta

We examine transport through a quantum dot coupled to three ferromagnetic leads in the regime of weak tunnel coupling. A finite source-drain voltage generates a nonequilibrium spin on the otherwise non-magnetic quantum dot. This spin…

Mesoscale and Nanoscale Physics · Physics 2007-09-28 Daniel Urban , Matthias Braun , Jürgen König

The ability to convert spin accumulation to charge currents is essential for applications in spintronics. In semiconductors, spin-to-charge conversion is typically achieved using the inverse spin Hall effect or using a large magnetic field.…

Mesoscale and Nanoscale Physics · Physics 2020-10-28 E. Marcellina , A. Srinivasan , F. Nichele , P. Stano , D. A. Ritchie , I. Farrer , Dimitrie Culcer , A. R. Hamilton