Spin-orbit coupling and electric-dipole spin resonance in a nanowire double quantum dot

Liu, Zhihai; Li, Rui; Hu, Xuedong; You, J. Q.

doi:10.1038/s41598-018-20706-5

Cited by 18 publications

(14 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We point out that this technique can also be applied to heavy-hole systems, where the control of the hole spin via the tunneling and strong SOC has been demonstrated for silicon-based DQDs [34]. Recent publications presenting theoretical proposals for DQD with strong SOC [19,20] and transverse magnetic field [35] are potentially consistent with our method and can be compared to other protocols based on the approach proposed here. Finally, a similar approach can be used to design the spin and mass transport of cold atoms in optically produced potentials [36].…”

Section: Discussionsupporting

confidence: 59%

“…The practical advantage of the Rashba coupling is the ability to manipulate it by an external electric field applied across the semiconductor structure [14,15]. The Rashba coupling controlled by a high-frequency ac gate voltage [16] provides an effective method to control the spin states in a short time [17][18][19][20] and produce exact nonadiabatic transformations for the electron in a parabolic potential [21].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Qubit gates with simultaneous transport in double quantum dots

Chen

Muga

et al. 2018

New J. Phys.

View full text Add to dashboard Cite

A single electron spin in a double quantum dot in a magnetic field is considered in terms of a four-level system. By describing the electron motion between the potential minima via spin-conserving tunneling and spin flip caused by a spin-orbit coupling, we inversely engineer faster-than-adiabatic state manipulation operations based on the geometry of four-dimensional rotations. In particular, we show how to transport a qubit among the quantum dots performing simultaneously required spin rotations. IntroductionDevice architecture based on electrons confined in coupled quantum dots [1-4] is considered as a potential and significant candidate for quantum computing and quantum information processing. The advantages of this architecture rely on the facts that electron spin is a natural qubit with spin-up and spin-down states, mature semiconductor technology may be used, and long coherence times on the scale of microseconds have been achieved in these systems [5,6]. Laboratories use electric, microwave or magnetic fields to manipulate spin states, performing 10 3 -10 5 operations in the spin dephasing time [5-10].Scalability of quantum information devices is a major challenge for any architecture, and it is associated with the capability to transport qubits. In this paper we theoretically explore a four-level model for a spin in a double quantum dot (DQD) aiming at the possibilities to implement fast qubit transport with simultaneous qubit rotations. We achieve this goal for arbitrary rotations by controlling the synchronized time dependences of interdot tunneling and spin-orbit coupling (SOC). We inverse-engineer these time dependences based on our recent work [11] on the control of four-level systems. The method separates population control from control of the phases of the bare state basis [12]. Populations can be mapped onto a four-dimensional (4D) sphere such that their evolution amounts to 4D transformation controlled by the (4D-)rotation Hamiltonian that may be engineered from the target state (in our case via isoclinic rotations and quaternions). A full Hamiltonian can then be constructed from the rotation Hamiltonian to realize the desired phase changes. Arbitrary state manipulations require full flexibility in the Hamiltonian, i.e. the possibility to implement the different Hamiltonian matrix elements with specific time-dependences. In the systems of interest, however, there are constraints that hinder certain manipulations and transitions. In particular, in this paper we examine the Hamiltonian structure that corresponds to combined tunneling and SOC controllable couplings, and deduce the possible transformations.Spin-orbit coupling in semiconductors consists of two main contributions due to the Dresselhaus-and the Bychkov-Rashba-effect. The former is due to the bulk inversion asymmetry of the material and the latter results from the structure inversion asymmetry, produced, e.g. by the confining potential or an external electric field [13]. The practical advantage of the Rashba coupling is the ability to man...

show abstract

Section: Discussionsupporting

confidence: 59%

mentioning

confidence: 99%

Qubit gates with simultaneous transport in double quantum dots

Chen

Muga

et al. 2018

New J. Phys.

View full text Add to dashboard Cite

show abstract

“…In gated GaAs or Si devices confining electrons, the spin-orbit interaction (SOI) inherent in the semiconductor material has also been exploited 5,6,11 ; however, the resulting coupling is weak so coherent control of the spin is possible only on timescales comparable to the spin decoherence time 6 . The SOI strength can be increased by confining electrons in InAs 12,13 or InSb dots 14 ; however, switching the carrier type to holes that can deliver strong SOI holds the greatest promise. EDSR in hole systems has been described theoretically 15,16 but to date demonstrated only in dots defined in silicon 17,18 or germanium 19 , for which the SOI is relatively weak owing to the inversion symmetry of the crystal lattice.…”

mentioning

confidence: 99%

Electrically tunable effective g-factor of a single hole in a lateral GaAs/AlGaAs quantum dot

et al. 2019

View full text Add to dashboard Cite

Electrical tunability of the g-factor of a confined spin is a long-time goal of the spin qubit field. Here we utilize the electric dipole spin resonance (EDSR) to demonstrate it in a gated GaAs double-dot device confining a hole. This tunability is a consequence of the strong spin-orbit interaction (SOI) in the GaAs valence band. The SOI enables a spin-flip interdot tunneling, which, in combination with the simple spin-conserving charge transport leads to the formation of tunable hybrid spin-orbit molecular states. EDSR is used to demonstrate that the gap separating the two lowest energy states changes its character from a charge-like to a spin-like excitation as a function of interdot detuning or magnetic field. In the spin-like regime, the gap can be characterized by the effective g-factor, which differs from the bulk value owing to spin-charge hybridization, and can be tuned smoothly and sensitively by gate voltages.

show abstract

“…It should be noted that, in the presence of the magnetic field, there is a vector potential term A x = −(y/2)B sin ϕ. However, for a quasi-1D quantum dot, we can set y = 0 because the motion of the electron is only allowed in the axial direction [28,37]. We first give the boundary condition of our model.…”

Section: The Modelmentioning

confidence: 99%

Spin-relaxation anisotropy in a nanowire quantum dot with strong spin-orbit coupling

Liu,

2018

Preprint

Self Cite

View full text Add to dashboard Cite

We study the impacts of the magnetic field direction on the spin-manipulation and the spinrelaxation in a one-dimensional quantum dot with strong spin-orbit coupling. The energy spectrum and the corresponding eigenfunctions in the quantum dot are obtained exactly. We find that no matter how large the spin-orbit coupling is, the electric-dipole spin transition rate as a function of the magnetic field direction always has a π periodicity. However, the phonon-induced spin relaxation rate as a function of the magnetic field direction has a π periodicity only in the weak spin-orbit coupling regime, and the periodicity is prolonged to 2π in the strong spin-orbit coupling regime.

show abstract

Spin-orbit coupling and electric-dipole spin resonance in a nanowire double quantum dot

Cited by 18 publications

References 65 publications

Qubit gates with simultaneous transport in double quantum dots

Qubit gates with simultaneous transport in double quantum dots

Electrically tunable effective g-factor of a single hole in a lateral GaAs/AlGaAs quantum dot

Spin-relaxation anisotropy in a nanowire quantum dot with strong spin-orbit coupling

Contact Info

Product

Resources

About