Hole transport in p-type GaAs quantum dots and point contacts

Grbić, Boris; Leturcq, R.; Ihn, Thomas; Ensslin, Klaus; Reuter, D.; Wieck, A. D.

doi:10.1063/1.2730121

Cited by 4 publications

(4 citation statements)

References 5 publications

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“…Such a situation can, in principle, be easily realized by tuning the lateral confinement via side gates in self-assembled 64,65 or lithographically defined nanowires, 66 or quantum point contacts. [67][68][69] Quasi-onedimensional (1D) hole systems thus provide an interesting laboratory for the study of spin-3/2 physics, as well as have the potential for being building blocks in hole-spintronics applications.…”

Section: Introductionmentioning

confidence: 99%

Spin-32physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings

et al. 2009

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We present a detailed theoretical study of the electronic spectrum and Zeeman splitting in hole quantum wires. The spin-3/2 character of the topmost bulk-valence-band states results in a strong variation of subband-edge g factors between different subbands. We elucidate the interplay between quantum confinement and heavy-holelight-hole mixing and identify a certain robustness displayed by low-lying hole-wire subband edges with respect to changes in the shape or strength of the wire potential. The ability to address individual subband edges in, e.g., transport or optical experiments enables the study of holes states with nonstandard spin polarization, which do not exist in spin-1/2 systems. Changing the aspect ratio of hole wires with rectangular cross-section turns out to strongly affect the g factor of subband edges, providing an opportunity for versatile in-situ tuning of hole-spin properties with possible application in spintronics. The relative importance of cubic crystal symmetry is discussed, as well as the spin splitting away from zone-center subband edges.

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Section: Introductionmentioning

confidence: 99%

Spin-32physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings

et al. 2009

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“…Nonetheless, decoherence and the control of decoherence is still an issue due to the ever present hyperfine interaction, and SOI for electrons in GaAs is comparatively weak (weaker than in other group III-V semiconductor systems such as InAs [52,53]). For these and other reasons, QD devices fabricated from GaAs/AlGaAs hetero-structures that confine holes have been on the radar for several years but have received less attention compared to their counterparts employing electrons due to technological difficulties: see [54][55][56][57][58][59][60][61][62] for work prior to our own. Important technological development was required with the GaAs material platform, particularly with p-type (modulation-doped) material, to overcome difficulties in fabrication, and issues related to telegraphic noise, sudden rearrangement of background charges, gate instability and hysteresis which initially limited studies of surfacegated low-dimensional hole devices [54,55,[57][58][59][60][61][63][64][65].…”

Section: Single-hole Spins As Qubitsmentioning

confidence: 99%

“…For these and other reasons, QD devices fabricated from GaAs/AlGaAs hetero-structures that confine holes have been on the radar for several years but have received less attention compared to their counterparts employing electrons due to technological difficulties: see [54][55][56][57][58][59][60][61][62] for work prior to our own. Important technological development was required with the GaAs material platform, particularly with p-type (modulation-doped) material, to overcome difficulties in fabrication, and issues related to telegraphic noise, sudden rearrangement of background charges, gate instability and hysteresis which initially limited studies of surfacegated low-dimensional hole devices [54,55,[57][58][59][60][61][63][64][65]. With recent advances, including the trend to populate QDs for holes electrostatically using a biased accumulation gate rather than by modulation doping, hole-spin-based electronic devices in planar GaAs/GaAlAs hetero-structures have evolved.…”

Section: Single-hole Spins As Qubitsmentioning

confidence: 99%

“…In this article, we will principally review our recent work on single-hole physics in a GaAs/AlGaAs DQD system [1][2][3][4][5]. We would nonetheless like to draw attention to the numerous other works involving planar GaAs/AlGaAs QW structures [54][55][56][57][58][59][60][61][62], and other semiconductor material platforms that have emerged, with which confined hole physics has been investigated by transport measurements of single-hole transistors, QD devices, and QD-like structures. The other hole material platforms comprise of InSb nano-wires [68]; planar Si metal oxide semiconductor field effect transistors (MOSFETs) ; planar Si/SiGe QWs [91]; Si nano-wires [92,93]; acceptor atoms in Si nano-wire transistors [94,95]; planar Ge/SiGe QWs [36,[96][97][98][99][100]; Ge hut wires [40,[101][102][103][104][105][106][107]; Ge nanowires [108]; Ge-Si core-shell nano-wires [37,[109][110][111][112][113][114][115]…”

Section: Single-hole Spins As Qubitsmentioning

confidence: 99%

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Single-hole physics in GaAs/AlGaAs double quantum dot system with strong spin–orbit interaction

Studenikin

Korkusiński

Bogan

et al. 2021

Semicond. Sci. Technol.

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There is rapidly expanding interest in exploiting the spin of valence-band holes rather than conduction-band electrons for spin qubit semiconductor circuits composed of coupled quantum dots. The hole platform offers stronger spin–orbit interaction (SOI), large difference between in-dot-plane and out-of-dot-plane g-factors, i.e. g-factor anisotropy, and a significantly reduced hyperfine coupling to nuclei in the host material. These attributes collectively can deliver fast all-electric coherent spin manipulation, efficient spin-flip inter-dot tunneling channels, a voltage tunable effective g-factor, a g-factor adjustable to nearly zero in an appropriately oriented external magnetic field, and long spin relaxation and coherence times. Here, we review our recent work on the physics of heavy holes confined in a planar GaAs/AlGaAs double quantum dot system with strong SOI. For a single-hole, we have performed resonant tunneling magneto-spectroscopy to extract spin-flip and spin-conserving tunneling strengths, implemented spin-flip Landau–Zener–Stückelberg–Majorana (LZSM) interferometry, determined the spin relaxation time T 1 as a function of magnetic field using a fast single-shot latched charge technique, electrically tuned the effective g-factor revealed by electric dipole spin resonance, and found signatures of the hyperfine interaction and dynamic nuclear polarization with holes. For two-holes, we have measured the energy spectrum in the presence of strong SOI (and so not limited by Pauli spin blockade), quantified the heavy-hole (HH) g-factor anisotropy on tilting the magnetic field, described a scheme to employ HHs whose g-factor is tunable to nearly zero for an in-plane magnetic field for a coherent photon-to-spin interface, and observed a well-defined LZSM interference pattern at small magnetic fields on pulsing through the singlet-triplet anti-crossing.

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Electrical control of single hole spins in nanowire quantum dots

et al. 2013

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Single electron spins in semiconductor quantum dots (QDs) are a versatile platform for quantum information processing, however controlling decoherence remains a considerable challenge. [1][2][3][4] Recently, hole spins have emerged as a promising alternative. Holes in III-V semiconductors have unique properties, such as strong spin-orbit interaction and weak coupling to nuclear spins, and therefore have potential for enhanced spin control 5-8 and longer coherence times 8-12 . Weaker hyperfine interaction has already been reported in self-assembled quantum dots using quantum optics techniques. 10-12 However, challenging fabrication has so far kept the promise of hole-spin-based electronic devices out of reach in conventional III-V heterostructures. 13 Here, we report gate-tuneable hole quantum dots formed in InSb nanowires. Using these devices we demonstrate Pauli spin blockade and electrical control of single hole spins. The devices are fully tuneable between hole and electron QDs, enabling direct comparison between the hyperfine interaction strengths, g-factors and spin blockade anisotropies in the two regimes.The development of viable quantum computation devices depends on the ability to preserve the coherence of quantum bits (qubits). 1 To date, most work in semiconductors has focused on using the spins of electrons as qubits. However, due to strong hyperfine coupling to the surrounding nuclear spin bath, electron spins experience rapid decoherence. [2][3][4] In contrast, the contact hyperfine interaction for hole spins is predicted to vanish due to the p-orbital symmetry of their Bloch wavefunction, leaving only the weaker dipole-dipole coupling. 9 However, a major technical challenge for investigating hole spins in gate-defined quantum dots has been that conventional p-doped quantum wells do not provide the required level of stability and tuneability. 13 An

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Hole transport in p-type GaAs quantum dots and point contacts

Cited by 4 publications

References 5 publications

Spin-32physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings

Spin-32physics of semiconductor hole nanowires: Valence-band mixing and tunable interplay between bulk-material and orbital bound-state spin splittings

Single-hole physics in GaAs/AlGaAs double quantum dot system with strong spin–orbit interaction

Electrical control of single hole spins in nanowire quantum dots

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