In a device with superconductor coupled to two parallel quantum dots (QDs) the electrical tunability of QD levels can be used exploit nonclassical current correlations due splitting Cooper pairs. We experimentally investigate effect finite potential difference across one dot on conductance through other completely grounded in pair splitter fabricated an InAs nanowire. demonstrate that nonlocal transport tuned by means and energy dependence effective density states QDs is relevant for rates...

We study the g-factor of discrete electron states in InAs nanowire based quantum dots. The g values are determined from magnetic field splitting zero bias anomaly due to spin 1/2 Kondo effect. Unlike previous studies on 2DEG dots, g-factors neighboring show a surprisingly large fluctuation: can scatter between 2 and 18. Furthermore electric gate tunability is demonstrated.

The break-junction technique is widely used to measure electronic properties of nanoscale junctions including metal point-contacts and single-molecule junctions. In these measurements, conductance measured as a function electrode displacement yielding data that analyzed by constructing histograms determine the most frequently observed values in However much rich physics measurements lost this simple analysis technique. Conductance cannot be study statistical relation distinct junction...

Cooper pair splitting (CPS) is a process in which the electrons of naturally occurring spin-singlet pairs superconductor are spatially separated using two quantum dots. Here, we investigate evolution conductance correlations an InAs CPS device presence external magnetic field. In our experiments gate dependence signal that depends on both dots continuously evolves from slightly asymmetric Lorentzian to strongly Fano-type resonance with increasing These can be understood simple three-site...

Coupling individual atoms fundamentally changes the state of matter: electrons bound to atomic cores become delocalized turning an insulating a metallic one. A chain could lead more exotic states if tunneling takes place via superconducting vacuum and can induce topologically protected excitations like Majorana or parafermions. Although coupling single atom superconductor is well studied, hybridization two sites with tunability was not reported yet. The peculiar Bardeen-Cooper-Schrieffer...

Abstract Van der Waals heterostructures composed of multiple few layer crystals allow the engineering novel materials with predefined properties. As an example, coupling graphene weakly to large spin–orbit (SOC) allows engineer a sizeable SOC in via proximity effects. The strength effect depends on overlap atomic orbitals, therefore, changing interlayer distance hydrostatic pressure can be utilized enhance between layers. In this work, we report measurements graphene/WSe 2 heterostructure...

Recent realization of minimal Kitaev chains brought a breakthrough in Majorana research, which made arrays quantum dots coupled by superconductor spacers the most promising synthetic material for topological architectures. In this paper, we investigate basic building block platform---two via (referred to as an Andreev molecule)---in configuration where two superconducting (SC) loops are created tune SC phase difference across dots. This enables us consider Coulomb interactions was not...

The ferromagnetic proximity effect is studied in InAs nanowire based quantum dots strongly coupled to a ($F$) and superconducting ($S$) lead. influence of the $F$ lead detected through splitting spin-$1/2$ Kondo resonance. We show that induces local exchange field on dot, which has varying amplitude sign depending charge states. interplay $S$ correlations generates an related subgap feature.

Indium arsenide (InAs) nanowires (NWs) are a promising platform to fabricate quantum electronic devices, among others they have strong spin-orbit interaction (SOI). The controlled tuning of the SOI is desired in spin based devices. In this study we investigate possibility by electrostatic field, which generated back gate and two side gates placed on opposite sides NW. strength analyzed weak anti-localization effect. We demonstrate that can be strongly tuned factor 2 with electric field...

A Cooper pair splitter consists of a central superconducting contact, S, from which electrons are injected into two parallel, spatially separated quantum dots (QDs). This geometry as well electron interactions can lead to correlated electrical currents due the spatial separation spin-singlet pairs S. We present experiments on such device with series bottom gates, allows for resolved tuning tunnel couplings between QDs and contacts QDs. Our main findings gate-induced transitions positive...

Abstract Hybrid nanostructures consisting of two parallel InAs nanowires connected by an epitaxially grown superconductor (SC) shell recently became available. Due to the defect-free SC-semiconductor interface and quasi-one-dimensional channels being close by, these platforms can be utilized spatially separate entangled pairs electrons using quantum dots (QD) in so-called Cooper pair splitting (CPS) process. The minimized distance between QDs overcomes limitations single-wire-based...

Understanding the microscopic origin of gate-controlled supercurrent (GCS) in superconducting nanobridges is crucial for engineering switches suitable a variety electronic applications. The GCS controversial, and various mechanisms have been proposed to explain it. In this work, we investigated Ta layer deposited on surface InAs nanowires. Comparison between switching current distributions at opposite gate polarities dependence two side gates with different nanowire-gate spacings shows that...

In conventional metal-oxide semiconductor (CMOS) electronics, the logic state of a device is set by gate voltage (VG). The superconducting equivalent such effect had remained unknown until it was recently shown that VG can tune current (supercurrent) flowing through nanoconstriction in superconductor. This gate-controlled supercurrent (GCS) lead to logics like CMOS logics, but with lower energy dissipation. physical mechanism underlying GCS, however, remains under debate. this review...

Spin orbit interaction is strongly enhanced in structures where a heavy element embedded an inversion asymmetric crystal field. A simple way for realizing such setup to take single atomic layer of and encapsulate it between two layers different elemental composition. BiTeI promising candidate 2D crystal. In its bulk form consists loosely coupled three atom thick high number Bi are sandwiched Te I sheets. Despite considerable recent attention due giant Rashba spin splitting, the isolation...

Ferromagnetic materials are the widely used source of spin-polarized electrons in spintronic devices, which controlled by external magnetic fields or spin-transfer torque methods. However, with increasing demand for smaller and faster components utilization spin–orbit phenomena provides promising alternatives. New unique spin textures highly desirable since all-electric creation control polarization is expected where strength, as well an arbitrary orientation polarization, can be defined...

Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which give a drive to the field of strongly correlated physics. In twisted double bilayer graphene dual gating allows changing Fermi level and hence electron density also tuning interlayer potential, giving further control over gaps. Here, we demonstrate that by applying hydrostatic pressure, an additional becomes possible due change tunnel couplings between...

Cooper pair splitting (CPS) is a way to create spatially separated, entangled electron pairs. To this day, CPS often identified in experiments as spatial current correlation. However, such correlations can arise even the absence of CPS, when quantum dot strongly coupled superconductor, and subgap Shiba state formed. Here, we present detailed experimental characterization those correlations, tunnel barrier strength between neighboring normal electrode tuned. The correlation nonlocal signal...

The control of a superconducting current via the application gate voltage has been recently demonstrated in variety devices. Although mechanism underlying this gate-controlled supercurrent (GCS) effect remains under debate, GCS raised great interest for development equivalent conventional metal-oxide semiconductor electronics. To date, however, mostly observed devices made by additive patterning. Here, we show that subtractive patterning systematic absence effect. Doing microstructural...

Hybrid systems consisting of highly transparent channels low-dimensional semiconductors between superconducting elements allow the formation quantum electronic circuits. Therefore, they are among novel material platforms that could pave way for scalable com-putation. To this aim, InAs two-dimensional electron gases ideal semiconductor due to their vanishing Schottky barrier; however, exploitation is limited by una-vailability commercial lattice-matched substrates. We show in situ growth...

Hybrid systems consisting of highly transparent channels low-dimensional semiconductors between superconducting elements allow the formation quantum electronic circuits. Therefore, they are among novel material platforms that could pave way for scalable computation. To this aim, InAs two-dimensional electron gases ideal semiconductor due to their vanishing Schottky barrier; however, exploitation is limited by unavailability commercial lattice-matched substrates. We show in situ growth...

Hybrid devices combining quantum dots with superconductors are important building blocks of conventional and topological quantum-information experiments. A requirement for the success such experiments is to understand various tunneling-induced non-local interaction mechanisms that present in devices, namely crossed Andreev reflection, elastic co-tunneling, direct interdot tunneling. Here, we provide a theoretical study simple device consists two superconductor tunnel-coupled dots, often...

Gate-controlled supercurrent (GCS) in superconducting nanobridges has recently attracted attention as a means to create switches. Despite the clear advantages for applications, microscopic mechanism of this effect is still under debate. In work, we realize GCS first time highly crystalline superconductor epitaxially grown on an InAs nanowire. We show that epitaxial Al layer can be switched normal state by applying ≃±23 V bottom gate insulated from nanowire hBN layer. Our extensive study...

The observation of the gate-controlled supercurrent (GCS) effect in superconducting nanostructures increased hopes for realizing a equivalent semiconductor field-effect transistors. However, recent works attribute this to various leakage-based scenarios, giving rise debate on its origin. A proper understanding microscopic process underlying GCS and relevant time scales would be beneficial evaluate possible applications. In work, we observed gate-induced two-level fluctuations between state...

Abstract Various promising qubit concepts have been put forward recently based on engineered superconductor subgap states like Andreev bound states, Majorana zero modes or the Yu-Shiba-Rusinov (Shiba) states. The coupling of these via a strongly depends their spatial extension and is an essential next step for future quantum technologies. Here we investigate Shiba state in semiconductor dot coupled to superconductor. With detailed transport measurements numerical renormalization group...