Spin-Echo Dynamics of a Heavy Hole in a Quantum Dot

Wang, Xiaoya Judy; Chesi, Stefano; Coish, W. A.

doi:10.1103/physrevlett.109.237601

Cited by 28 publications

(49 citation statements)

References 36 publications

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“…While φ is Gaussian-distributed, L[φ] is a highly nonlinear function of φ, making a direct Gaussian average difficult. In general, we would like an expansion valid up to time scales t T φ (giving φ 1), so an expansion for small φ, which was justified in evaluating the longitudinal spin S x (2τ ) , 35 is not generally possible for the coherence factor. Instead, here we perform a moment expansion, valid for |L| 1,…”

Section: Pure Dephasingmentioning

confidence: 99%

“…We consider a model Hamiltonian, appropriate for a heavy-hole spin qubit in a flat semiconductor quantum dot 35 with an in-plane magnetic field applied along the x-axis [see Fig. 1…”

Section: A Hole-spin Modelmentioning

confidence: 99%

“…Anisotropic hyperfine couplings between a central qubit spin and environmental spins are important for nitrogen-vacancy centers in diamond, [26][27][28] electrons bound to phosphorus donor impurities in silicon, 29,30 electrons in graphene or carbon nanotubes, 31,32 and especially for hole spins in III-V semiconductors or silicon. [33][34][35][36][37] Heavy-hole spins can indeed approach the extreme-anisotropic limit of a pure Ising-like coupling to nuclear spins. 33 Finally, singlettriplet (S-T 0 ) qubits, describing two electrons in a double quantum dot, are described by precisely the same anisotropic decoherence model 38 as a heavy-hole spin qubit (see Fig.…”

Section: Introductionmentioning

confidence: 99%

“…53 The very recent achievement of the few-hole regime in lateral gated double-dot devices, 54 suggests that previous highly successful measurements performed for electron spins [55][56][57][58][59][60] can now be performed for hole spins, which show promise for much longer coherence times. 33,35 In the rest of this paper, we introduce a general method that can be used to calculate and enhance the purity of a qubit interacting with an anisotropic environment. We apply this method to the experimentally relevant problems of heavy-hole and singlet-triplet (S-T 0 ) spin-echo and dynamical-decoupling dynamics.…”

Section: Introductionmentioning

confidence: 99%

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Maximizing the purity of a qubit evolving in an anisotropic environment

2015

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We provide a general method to calculate and maximize the purity of a qubit interacting with an anisotropic non-Markovian environment. Counter to intuition, we find that the purity is often maximized by preparing and storing the qubit in a superposition of non-interacting eigenstates. For a model relevant to decoherence of a heavy-hole spin qubit in a quantum dot or for a singlettriplet qubit for two electrons in a double quantum dot, we show that preparation of the qubit in its non-interacting ground state can actually be the worst choice to maximize purity. We further give analytical results for spin-echo envelope modulations of arbitrary spin components of a hole spin in a quantum dot, going beyond a standard secular approximation. We account for general dynamics in the presence of a pure-dephasing process and identify a crossover timescale at which it is again advantageous to initialize the qubit in the non-interacting ground state. Finally, we consider a general two-axis dynamical decoupling sequence and determine initial conditions that maximize purity, minimizing leakage to the environment.

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Section: Pure Dephasingmentioning

confidence: 99%

“…We consider a model Hamiltonian, appropriate for a heavy-hole spin qubit in a flat semiconductor quantum dot 35 with an in-plane magnetic field applied along the x-axis [see Fig. 1…”

Section: A Hole-spin Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Maximizing the purity of a qubit evolving in an anisotropic environment

2015

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“…In Sec. 4 we will focus on a review of recent theoretical work exploring related hole-spin-echo decay in experimentally accessible regimes [69].…”

Section: -Introductionmentioning

confidence: 99%

Controlling hole spins in quantum dots and wells

2014

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Summary. -We review recent theoretical results for hole spins influenced by spin-orbit coupling and Coulomb interaction in two-dimensional quantum wells as well as the decoherence of single hole spins in quantum dots due to hyperfine interaction with surrounding nuclear spins. After reviewing the different forms of spin-orbit coupling that are relevant for electrons and heavy holes in III-V semiconductor quantum wells, we illustrate the combined effect of spin-orbit coupling and Coulomb interactions for hole systems on spin-dependent quasiparticle group velocities. We further analyze spin-echo decay for a single hole spin in a nuclear-spin bath, demonstrating that this decoherence source can be controlled in these systems by entering a motional-averaging regime. Throughout this review, we emphasize physical effects that are unique to hole spins (rather than electrons) in nanoscale systems.

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Single hole spin relaxation probed by fast single-shot latched charge sensing

et al. 2019

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Hole spins have recently emerged as attractive candidates for solid-state qubits for quantum computing. Their state can be manipulated electrically by taking advantage of the strong spinorbit interaction (SOI). Crucially, these systems promise longer spin coherence lifetimes owing to their weak interactions with nuclear spins as compared to electron spin qubits. Here we measure the spin relaxation time T 1 of a single hole in a GaAs gated lateral double quantum dot device. We propose a protocol converting the spin state into long-lived charge configurations by the SOI-assisted spin-flip tunneling between dots. By interrogating the system with a charge detector we extract the magnetic-field dependence of T 1 ∝ B −5 for fields larger than B = 0.5 T, suggesting the phonon-assisted Dresselhaus SOI as the relaxation channel. This coupling limits the measured values of T 1 from~400 ns at B = 1.5 T up tõ 60 μs at B = 0.5 T.

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Spin-Echo Dynamics of a Heavy Hole in a Quantum Dot

Cited by 28 publications

References 36 publications

Maximizing the purity of a qubit evolving in an anisotropic environment

Maximizing the purity of a qubit evolving in an anisotropic environment

Controlling hole spins in quantum dots and wells

Single hole spin relaxation probed by fast single-shot latched charge sensing

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