Conduction electrons and the decoherence of impurity-bound electrons in a semiconductor

Virk, Kuljit S.; Sipe, J. E.

doi:10.1103/physrevb.72.155312

Cited by 5 publications

(8 citation statements)

References 26 publications

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“…Yet the observed magnetic field dependence has still to be explained by theory [511]. Before turning to experimental studies, it should be mentioned that to date there have only been a few theoretical works on spin relaxation in the insulating regime [39,40,[322][323][324]324,325,443,507,510,512,513], more studies are needed. In particular, hole spin relaxation in the insulating regime was discussed only in Ref.…”

Section: Carrier Spin Relaxation At Low Temperature In the Insulatingmentioning

confidence: 96%

Spin dynamics in semiconductors

2010

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This article reviews the current status of spin dynamics in semiconductors which has achieved a lot of progress in the past years due to the fast growing field of semiconductor spintronics. The primary focus is the theoretical and experimental developments of spin relaxation and dephasing in both spin precession in time domain and spin diffusion and transport in spacial domain. A fully microscopic many-body investigation on spin dynamics based on the kinetic spin Bloch equation approach is reviewed comprehensively.Comment: a review article with 193 pages and 1103 references. To be published in Physics Reports

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Section: Carrier Spin Relaxation At Low Temperature In the Insulatingmentioning

confidence: 96%

Spin dynamics in semiconductors

2010

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“…We begin with a generic approach for coupling to the incoherent environment, based on the conventional Lindblad formalism as can arise, e.g., from interaction with the conduction electron bath. The master equation reads [32] …”

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confidence: 99%

Fast and Robust Spin Manipulation in a Quantum Dot by Electric Fields

Ban¹,

Chen²,

Sherman³

et al. 2012

Phys. Rev. Lett.

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We apply an invariant-based inverse engineering method to control by time-dependent electric fields electron spin dynamics in a quantum dot with spin-orbit coupling in a weak magnetic field. The designed electric fields provide a shortcut to adiabatic processes that flips the spin rapidly, thus avoiding decoherence effects. This approach, being robust with respect to the device-dependent noise, can open new possibilities for the spin-based quantum information processing.PACS numbers: 73.63. Kv, 72.25.Dc, 72.25.Pn Coherent spin manipulation in quantum dots (QDs) [1][2][3][4][5][6][7][8][9] is the key element in the state-of-the-art spintronics and solid-state quantum information [10,11]. Accurate spin manipulation can be achieved by several techniques. One of them is the conventional electron spin resonance induced by a magnetic field oscillating at the Zeeman transition frequency [1]. A more robust technique is the spin manipulation with geometric Berry phases during adiabatic motion [2,3]. Nowadays, there is also a growing interest in the electric control of spin using spin-orbit (SO) coupling [12]. It has been applied to high-fidelity spin manipulation on the 100 ns time scale [7][8][9]. This highly efficient all-electrical method has several advantages. For example, it is easy to generate time-dependent electric fields on the nanoscale by adding local electrodes and produce spin manipulation by making them Zeemanresonant [7]. As a result, Rabi spin oscillations appear at a frequency much smaller than the Zeeman frequency making the flip relatively slow and prone to decoherence. We shall propose here another all-electrical technique to flip spin with high fidelity via "shortcuts to adiabaticity", in a time that can be much shorter than any decoherence time.Recently, several shortcuts to adiabaticity have been put forward to speed up the adiabatic passage of quantum systems, and achieve a robust and fast adiabatic-like control [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The transitionless or counter-diabatic control algorithms proposed by Demirplak, Rice [13], and Berry [14], are designed to add supplementary timedependent interactions that cancel the diabatic couplings of a reference process. The system then follows exactly the adiabatic trajectory of the original unperturbed process, in principle in an arbitrarily short time. Transitionless quantum drivings have been implemented in two-level systems: spins in a magnetic field [14], atoms [15], and Bose-Einstein condensates in optical lattices [16]. A different shortcut is provided by inverse engineering the transient Hamiltonian [17,18] using LewisRiesenfeld invariants [27]. This method has been used for time-dependent traps [17-21], atomic transport [22], and other applications [23,24]. Although these two methods are potentially equivalent [25], their implementations and results can be quite different. Here we choose the invariant-based inverse engineering approach, since it is better suited than the transitionless driving to be produced by ...

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“…To study the decoherence effect, we present the master equation for the density matrix36 in a generic form: where γ is the dephasing rate. Solving the Bloch equation, we can obtain the final fidelity ( F = ρ 11 ) for different times, see Fig.…”

Section: Discussionmentioning

confidence: 99%

“…For a realistic setup, the coupling to the stochastic environment is a general scenario to be considered, where the hyperfine interactions with the nuclear spin could play important role at low temperature. To study the decoherence effect, we present the master equation for the density matrix 36 in a generic form: where γ is the dephasing rate. Solving the Bloch equation, we can obtain the final fidelity ( F = ρ 11 ) for different times, see Fig.…”

Section: Discussionmentioning

confidence: 99%

Counter-diabatic driving for fast spin control in a two-electron double quantum dot

Ban

Chen

2014

Sci Rep

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The techniques of shortcuts to adiabaticity have been proposed to accelerate the “slow” adiabatic processes in various quantum systems with the applications in quantum information processing. In this paper, we study the counter-diabatic driving for fast adiabatic spin manipulation in a two-electron double quantum dot by designing time-dependent electric fields in the presence of spin-orbit coupling. To simplify implementation and find an alternative shortcut, we further transform the Hamiltonian in term of Lie algebra, which allows one to use a single Cartesian component of electric fields. In addition, the relation between energy and time is quantified to show the lower bound for the operation time when the maximum amplitude of electric fields is given. Finally, the fidelity is discussed with respect to noise and systematic errors, which demonstrates that the decoherence effect induced by stochastic environment can be avoided in speeded-up adiabatic control.

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Conduction electrons and the decoherence of impurity-bound electrons in a semiconductor

Cited by 5 publications

References 26 publications

Spin dynamics in semiconductors

Spin dynamics in semiconductors

Fast and Robust Spin Manipulation in a Quantum Dot by Electric Fields

Counter-diabatic driving for fast spin control in a two-electron double quantum dot

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