English
Related papers

Related papers: Control of spin relaxation in semiconductor double…

200 papers

We study the relaxation of an electron spin qubit in a Si quantum dot due to electrical noise. In particular, we clarify how the presence of conduction-band valleys influences spin relaxation. In single-valley semiconductor quantum dots,…

Mesoscale and Nanoscale Physics · Physics 2014-12-24 Peihao Huang , Xuedong Hu

We expand on previous work that treats relaxation physics of low-lying excited states in ideal, single electron, silicon quantum dots in the context of quantum computing. These states are of three types: orbital, valley, and spin. The…

Mesoscale and Nanoscale Physics · Physics 2014-02-12 Charles Tahan , Robert Joynt

Long-range quantum communication for spin qubits is an important open problem. Here we study decoherence of an electron spin qubit that is being transported in a moving quantum dot. We focus on spin decoherence due to spin-orbit interaction…

Mesoscale and Nanoscale Physics · Physics 2013-08-12 Peihao Huang , Xuedong Hu

We have studied theoretically the possibility of ultra-fast manipulation of a single electron spin in 2D semiconductor quantum dots, by means of high-frequency time-dependent electric fields. The electron spin degree of freedom is excited…

Mesoscale and Nanoscale Physics · Physics 2014-10-24 J. A. Budagosky , A. Castro

We discuss the rate of relaxation of the total spin in the two-electron droplet in the vicinity of the magnetic field driven singlet-triplet transition. The total spin relaxation is attributed to spin-orbit and electron-phonon interactions.…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 S. Dickmann , P. Hawrylak

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 study the mechanism of nuclear spin relaxation in quantum dots due to the electron exchange with 2D gas. We show that the nuclear spin relaxation rate is dramatically affected by the Coulomb blockade and can be controlled by gate…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Y. B. Lyanda-Geller , I. L. Aleiner , B. L. Altshuler

Although silicon is a promising material for quantum computation, the degeneracy of the conduction band minima (valleys) must be lifted with a splitting sufficient to ensure formation of well-defined and long-lived spin qubits. Here we…

Mesoscale and Nanoscale Physics · Physics 2013-07-01 C. H. Yang , A. Rossi , R. Ruskov , N. S. Lai , F. A. Mohiyaddin , S. Lee , C. Tahan , G. Klimeck , A. Morello , A. S. Dzurak

We show how the optical properties of a single semiconductor quantum dot can be controlled with a small dc voltage applied to a gate electrode. We find that the transmission spectrum of the neutral exciton exhibits two narrow lines with…

Mesoscale and Nanoscale Physics · Physics 2012-09-18 A. Högele , S. Seidl , M. Kroner , K. Karrai , R. J. Warburton , B. D. Gerardot , P. M. Petroff

We report on measurements of the spin relaxation time T1 of individual electron spins in the few electron regime of a Si/SiO2-based quantum dot (QD). Energy-spectroscopy of the QD has been performed using a charge sensing technique. The…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 M. Xiao , M. G. House , H. W. Jiang

We have studied theoretically the electron spin relaxation in semiconductor quantum dots via interaction with nuclear spins. The relaxation is shown to be determined by three processes: (i) -- the precession of the electron spin in the…

Condensed Matter · Physics 2009-11-07 I. A. Merkulov , Al. L. Efros , M. Rosen

Electron states in a inhomogeneous Ge/Si quantum dot array with groups of closely spaced quantum dots were studied by conventional continuous wave ($cw$) ESR and spin-echo methods. We find that the existence of quantum dot groups allows to…

Mesoscale and Nanoscale Physics · Physics 2014-12-23 A. F. Zinovieva , N. P. Stepina , A. I. Nikiforov , A. V. Nenashev , A. V. Dvurechenskii , L. V. Kulik , N. A. Sobolev , M. C. Carmo

We consider a double quantum dot system with two embedded and non-aligned spin impurities to manipulate the magnitude and polarization of the electron spin density. The device is attached to semi-infinite one-dimensional leads which are…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Gianluca Stefanucci , Enrico Perfetto , Michele Cini

Spins in gate-defined silicon quantum dots are promising candidates for implementing large-scale quantum computing. To read the spin state of these qubits, the mechanism that has provided the highest fidelity is spin-to-charge conversion…

We present a numerical study of spin relaxation in a semiclassical electron ensemble in a large ballistic quantum dot. The dot is defined in a GaAs/AlGaAs heterojunction system with a two-dimensional electron gas, and relaxation occurs due…

Mesoscale and Nanoscale Physics · Physics 2008-04-21 E. J. Koop , B. J. van Wees , C. H. van der Wal

We calculate the dynamical fluctuation spectrum of electronic spins in a semiconductor under a steady-state illumination by light containing polarization squeezing correlations. Taking into account quasi-particle lifetime and spin…

Other Condensed Matter · Physics 2009-11-13 Eran Ginossar , Yehoshua Levinson , Shimon Levit

We describe an interaction mechanism between electron spins in a vertically-stacked double quantum dot that can be used for controlled two-qubit operations. This interaction is mediated by excitons confined within, and delocalized over, the…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 C. Emary , L. J. Sham

We investigate coherent time-evolution of charge states (pseudo-spin qubit) in a semiconductor double quantum dot. This fully-tunable qubit is manipulated with a high-speed voltage pulse that controls the energy and decoherence of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Toshiaki Hayashi , Toshimasa Fujisawa , Hai-Du Cheong , Yoon-Ha Jeong , Yoshiro Hirayama

The phonon-induced spin relaxation in a two-dimensional quantum dot embedded inside a semiconductor slab is investigated theoretically. An enhanced relaxation rate is found due to the phonon van Hove singularities. Oppositely, a vanishing…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Y. Y. Liao , Y. N. Chen , D. S. Chuu , T. Brandes

The spin relaxation time $T_{1}$ in zinc blende GaN quantum dot is investigated for different magnetic field, well width and quantum dot diameter. The spin relaxation caused by the two most important spin relaxation mechanisms in zinc…

Materials Science · Physics 2009-04-11 M. Q. Weng , Y. Y. Wang , M. W. Wu