Tuning the Two-Electron Hybridization and Spin States in Parallel-Coupled InAs Quantum Dots

Nilsson, Magnus; Boström, Florinda Viñas; Lehmann, Sebastian; Dick, Kimberly A.; Leijnse, Martin; Thelander, Claes

doi:10.1103/physrevlett.121.156802

Cited by 22 publications

(23 citation statements)

References 34 publications

(44 reference statements)

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“…The extracted | g *| ~ 3 at orbital degeneracy should be considered an upper bound as it is difficult to find the specific angle where no external field penetrates the ring. When the ring is quenched by detuning, | g *| approaches 7.5, which is in line with typical values observed in InAs QDs 23,28 . The peak of d g */d Δ V L,R corresponds to >100 V −1 .…”

Section: Resultssupporting

confidence: 88%

Electrical control of spins and giant g-factors in ring-like coupled quantum dots

et al. 2019

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Emerging theoretical concepts for quantum technologies have driven a continuous search for structures where a quantum state, such as spin, can be manipulated efficiently. Central to many concepts is the ability to control a system by electric and magnetic fields, relying on strong spin-orbit interaction and a large g-factor. Here, we present a mechanism for spin and orbital manipulation using small electric and magnetic fields. By hybridizing specific quantum dot states at two points inside InAs nanowires, nearly perfect quantum rings form. Large and highly anisotropic effective g-factors are observed, explained by a strong orbital contribution. Importantly, we find that the orbital contributions can be efficiently quenched by simply detuning the individual quantum dot levels with an electric field. In this way, we demonstrate not only control of the effective g-factor from 80 to almost 0 for the same charge state, but also electrostatic change of the ground state spin.

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Section: Resultssupporting

confidence: 88%

Electrical control of spins and giant g-factors in ring-like coupled quantum dots

et al. 2019

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“…Discussion -Similar observations of a couplingdependent energy splitting have been made for zerodimensional quantum dots [39] and two-dimensional layered van der Waals heterostructures [40]. In the latter case the opening of band-gaps was particularly prominent for out-of-plane-oriented MoS 2 orbitals which strongly overlap with graphene π-bands [40].…”

Section: Introduction -supporting

confidence: 70%

A Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator

Jung,

Odobesko,

Boshuis

et al. 2021

Preprint

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The interaction of spin-polarized one-dimensional (1D) topological edge modes localized along single-atomic steps of the topological crystalline insulator Pb0.7Sn0.3Se(001) has been studied systematically by scanning tunneling spectroscopy. Our results reveal that the coupling of adjacent edge modes sets in at a step-to-step distance dss ≤ 25 nm, resulting in a characteristic splitting of a single peak at the Dirac point in tunneling spectra. Whereas the energy splitting exponentially increases with decreasing dss for single-atomic steps running almost parallel, we find no splitting for single-atomic step edges under an angle of 90 • . The results are discussed in terms of overlapping wave functions with px, py orbital character.

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“…These QDs are electrically and spatially well defined, which allows us to probe the induced gap at a precise distance from the QD and with predictable coupling parameters. In-situ grown barriers have previously been used to investigate double QD physics 17,18 .…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy of the superconducting proximity effect in nanowires using integrated quantum dots

et al. 2019

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The superconducting proximity effect has been the focus of significant research efforts over many years and has recently attracted renewed interest as the basis of topologically nontrivial states in materials with a large spin orbit interaction, with protected boundary states useful for quantum information technologies. However, spectroscopy of these states is challenging because of the limited spatial and energetic control of conventional tunnel barriers.Here, we report electronic spectroscopy measurements of the proximity gap in a semiconducting indium arsenide (InAs) nanowire (NW) segment coupled to a superconductor (SC), using a spatially separated quantum dot (QD) formed deterministically during the crystal growth. We extract the characteristic parameters describing the proximity gap which is suppressed for lower electron densities and fully developed for larger ones. This gate-tunable transition of the proximity effect can be understood as a transition from the long to the short junction regime of subgap bound states in the NW segment. Our device architecture opens up the way to systematic, unambiguous spectroscopy studies of subgap bound states, such as 1 arXiv:1812.06850v1 [cond-mat.mes-hall]

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Tuning the Two-Electron Hybridization and Spin States in Parallel-Coupled InAs Quantum Dots

Cited by 22 publications

References 34 publications

Electrical control of spins and giant g-factors in ring-like coupled quantum dots

Electrical control of spins and giant g-factors in ring-like coupled quantum dots

A Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator

Spectroscopy of the superconducting proximity effect in nanowires using integrated quantum dots

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