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Realization of a minimal Kitaev chain in coupled quantum dots

Dvir, T. (author), Wang, Guanzhong (author), van Loo, N. (author), Liu, C. (author), Mazur, G.P. (author), Bordin, A. (author), ten Haaf, S.L.D. (author), van Driel, D. (author), Zatelli, F. (author), Li, X. (author), Malinowski, F.K. (author), Gazibegovic, Sasa (author), Badawy, G.H.A. (author), Bakkers, Erik P.A.M. (author), Wimmer, M.T. (author), Kouwenhoven, Leo P. (author)

Majorana bound states constitute one of the simplest examples of emergent non-Abelian excitations in condensed matter physics. A toy model proposed by Kitaev shows that such states can arise at the ends of a spinless p-wave superconducting chain¹. Practical proposals for its realization^2,3 require coupling neighbouring...

journal article 2023

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Magnetic-Field-Resilient Superconducting Coplanar-Waveguide Resonators for Hybrid Circuit Quantum Electrodynamics Experiments

Kroll, J. (author), Borsoi, F. (author), van der Enden, K.L. (author), Uilhoorn, W. (author), de Jong, D. (author), Quintero Perez, M. (author), van Woerkom, D.J. (author), Bruno, A. (author), Plissard, S. R. (author), Car, D. (author), Bakkers, E.P.A.M. (author), Cassidy, M.C. (author), Kouwenhoven, Leo P. (author)

Superconducting coplanar-waveguide resonators that can operate in strong magnetic fields are important tools for a variety of high-frequency superconducting devices. Magnetic fields degrade resonator performance by creating Abrikosov vortices that cause resistive losses and frequency fluctuations or suppress the superconductivity entirely. To...

journal article 2019

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Quantized Majorana conductance

Zhang, H. (author), Liu, Chun Xiao (author), Gazibegovic, S. (author), Xu, D. (author), Logan, John A. (author), Wang, Guanzhong (author), van Loo, N. (author), Bommer, J.D.S. (author), de Moor, M.W.A. (author), Car, D. (author), op het Veld, R.L.M. (author), Van Veldhoven, Petrus J. (author), Kölling, S. (author), Verheijen, M.P.A.M. (author), Pendharkar, Mihir (author), Pennachio, Daniel J. (author), Shojaei, Borzoyeh (author), Lee, Joon Sue (author), Palmstrøm, Chris J. (author), Bakkers, E.P.A.M. (author), Sarma, S. Das (author), Kouwenhoven, Leo P. (author)

Majorana zero-modes - a type of localized quasiparticle - hold great promise for topological quantum computing. Tunnelling spectroscopy in electrical transport is the primary tool for identifying the presence of Majorana zero-modes, for instance as a zero-bias peak in differential conductance. The height of the Majorana zero-bias peak is...

journal article 2018

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Electric field tunable superconductor-semiconductor coupling in Majorana nanowires

de Moor, M.W.A. (author), Bommer, J.D.S. (author), Xu, D. (author), Winkler, Georg W. (author), Antipov, Andrey E. (author), Bargerbos, A. (author), Wang, Guanzhong (author), van Loo, N. (author), op het Veld, R.L.M. (author), Gazibegovic, S. (author), Car, D. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, Leo P. (author), Zhang, H. (author)

We study the effect of external electric fields on superconductor-semiconductor coupling by measuring the electron transport in InSb semiconductor nanowires coupled to an epitaxially grown Al superconductor. We find that the gate voltage induced electric fields can greatly modify the coupling strength, which has consequences for the proximity...

journal article 2018

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Parity transitions in the superconducting ground state of hybrid InSb-Al Coulomb islands

Shen, J. (author), Heedt, S. (author), Borsoi, F. (author), van Heck, B. (author), Gazibegovic, S. (author), op het Veld, R.L.M. (author), Car, D. (author), Ramakers, S.J.J. (author), Wang, Guanzhong (author), Xu, D. (author), Bouman, D. (author), Geresdi, A. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, Leo P. (author)

The number of electrons in small metallic or semiconducting islands is quantised. When tunnelling is enabled via opaque barriers this number can change by an integer. In superconductors the addition is in units of two electron charges (2e), reflecting that the Cooper pair condensate must have an even parity. This ground state (GS) is...

journal article 2018

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Realization of Microwave Quantum Circuits Using Hybrid Superconducting Semiconducting Nanowire Josephson Elements

De Lange, G. (author), Van Heck, B. (author), Bruno, A. (author), Van Woerkom, D.J. (author), Geresdi, A. (author), Plissard, S.R. (author), Bakkers, E.P.A.M. (author), Akhmerov, A.R. (author), Di Carlo, L. (author)

We report the realization of quantum microwave circuits using hybrid superconductor-semiconductor Josephson elements comprised of InAs nanowires contacted by NbTiN. Capacitively shunted single elements behave as transmon circuits with electrically tunable transition frequencies. Two-element circuits also exhibit transmonlike behavior near zero...

journal article 2015

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Efficient water reduction with gallium phosphide nanowires

Standing, A. (author), Assali, S. (author), Gao, L. (author), Verheijen, M.A. (author), Van Dam, D. (author), Cui, Y. (author), Notten, P.H.L. (author), Haverkort, J.E.M. (author), Bakkers, E.P.A.M. (author)

Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite...

journal article 2015

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Spin-orbit interaction in InSb nanowires

Van Weperen, I. (author), Tarasinski, B. (author), Eeltink, D. (author), Pribiag, V.S. (author), Plissard, S.R. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author), Wimmer, M.T. (author)

We use magnetoconductance measurements in dual-gated InSb nanowire devices, together with a theoretical analysis of weak antilocalization, to accurately extract spin-orbit strength. In particular, we show that magnetoconductance in our three-dimensional wires is very different compared to wires in two-dimensional electron gases. We obtain a...

journal article 2015

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Quantum computing based on semiconductor nanowires

Frolov, S.M. (author), Plissard, S.R. (author), Nadj-Perge, S. (author), Kouwenhoven, L.P. (author), Bakkers, E.P.A.M. (author)

A quantum computer will have computational power beyond that of conventional computers, which can be exploited for solving important and complex problems, such as predicting the conformations of large biological molecules. Materials play a major role in this emerging technology, as they can enable sophisticated operations, such as control over...

journal article 2013

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Mapping the directional emission of quasi-two-dimensional photonic crystals of semiconductor nanowires using Fourier microscopy

Fontana, Y. (author), Grzela, G. (author), Bakkers, E.P.A.M. (author), Gomez Rivas, J. (author)

Controlling the dispersion and directionality of the emission of nanosources is one of the major goals of nanophotonics research. This control will allow the development of highly efficient nanosources even at the single-photon level. One of the ways to achieve this goal is to couple the emission to Bloch modes of periodic structures. Here, we...

journal article 2012

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Suppression of Zeeman Gradients by Nuclear Polarization in Double Quantum Dots

Frolov, S.M. (author), Danon, J. (author), Nadj-Perge, S. (author), Zuo, K. (author), Van Tilburg, J.W.W. (author), Pribiag, V.S. (author), Van den Berg, J.W.G. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author)

We use electric dipole spin resonance to measure dynamic nuclear polarization in InAs nanowire quantum dots. The resonance shifts in frequency when the system transitions between metastable high and low current states, indicating the presence of nuclear polarization. We propose that the low and the high current states correspond to different...

journal article 2012

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Spectroscopy of Spin-Orbit Quantum Bits in Indium Antimonide Nanowires

Nadj-perge, S. (author), Pribiag, V.S. (author), Van den Berg, J.W.G. (author), Zuo, K. (author), Plissard, S.R. (author), Bakkers, E.P.A.M. (author), Frolov, S.M. (author), Kouwenhoven, L.P. (author)

A double quantum dot in the few-electron regime is achieved using local gating in an InSb nanowire. The spectrum of two-electron eigenstates is investigated using electric dipole spin resonance. Singlet-triplet level repulsion caused by spin-orbit interaction is observed. The size and the anisotropy of singlet-triplet repulsion are used to...

journal article 2012

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Spontaneous emission control of single quantum dots in bottom-up nanowire waveguides

Bulgarini, G. (author), Reimer, M.E. (author), Zehender, T. (author), Hocevar, M. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author), Zwiller, V. (author)

Nanowire waveguides with controlled shape are promising for engineering the collection efficiency of quantum light sources. We investigate the exciton lifetime in individual InAsP quantum dots, perfectly positioned on-axis of InP nanowire waveguides. We demonstrate control over the quantum dot spontaneous emission by varying the nanowire...

journal article 2012

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Position-controlled [100] InP nanowire arrays

Wang, J. (author), Plissard, S. (author), Hocevar, M. (author), Vu, T.T.T. (author), Zehender, T. (author), Immink, G.G.W. (author), Verheijen, M.A. (author), Haverkort, J. (author), Bakkers, E.P.A.M. (author)

We investigate the growth of vertically standing [100] zincblende InP nanowire (NW) arrays on InP (100) substrates in the vapor-liquid-solid growth mode using low-pressure metal-organic vapor-phase epitaxy. Precise positioning of these NWs is demonstrated by electron beam lithography. The vertical NW yield can be controlled by different...

journal article 2012

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Strong modification of the reflection from birefringent layers of semiconductor nanowires by nanoshells

Diedenhofen, S.L. (author), Algra, R.E. (author), Bakkers, E.P.A.M. (author), Gómez Rivas, J. (author)

The propagation of light in layers of vertically aligned nanowires is determined by their unique and extreme optical properties. Depending on the nanowire filling fraction and their diameter, layers of nanowires form strongly birefringent media. This large birefringence gives rise to sharp angle dependent peaks in polarized reflection. We...

journal article 2011

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Grote toekomst voor kleine materialen

Bakkers, E.P.A.M. (author)

public lecture 2011

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Single quantum dot nanowire photodetectors

Van Kouwen, M.P. (author), Van Weert, M.H.M. (author), Reimer, M.E. (author), Akopian, N. (author), Perinetti, U. (author), Algra, R.E. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author), Zwiller, V. (author)

We report InP nanowire photodetectors with a single InAsP quantum dot as light absorbing element. With excitation above the InP band gap, the nanowire photodetectors are efficient (quantum efficiency of 4%). Under resonant excitation of the quantum dot, the photocurrent amplitude depends on the linear polarization direction of the incident light...

journal article 2010

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Surround-gated vertical nanowire quantum dots

Van Weert, M.H.M. (author), Den Heijer, M. (author), Van Kouwen, M.P. (author), Algra, R.E. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author), Zwiller, V. (author)

We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the anisotropic exchange splitting by polarization analysis,...

journal article 2010

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Disentangling the effects of spin-orbit and hyperfine interactions on spin blockade

Nadj-Perge, S. (author), Frolov, S.M. (author), Van Tilburg, J.W.W. (author), Danon, J. (author), Nazarov, Y.V. (author), Algra, R. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author)

We have achieved the few-electron regime in InAs nanowire double quantum dots. Spin blockade is observed for the first two half-filled orbitals, where the transport cycle is interrupted by forbidden transitions between triplet and singlet states. Partial lifting of spin blockade is explained by spin-orbit and hyperfine mechanisms that enable...

journal article 2010

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Surface passivated InAs/InP core/shell nanowires

Van Tilburg, J.W.W. (author), Algra, R.E. (author), Immink, W.G.G. (author), Verheijen, M. (author), Bakkers, E.P.A.M. (author), Kouwenhoven, L.P. (author)

We report the growth and characterization of InAs nanowires capped with a 0.5–1 nm epitaxial InP shell. The low-temperature field-effect mobility is increased by a factor 2–5 compared to bare InAs nanowires. We extract the highest low-temperature peak electron mobilities obtained for nanowires to this date, exceeding 20 000 cm2 V s?1. The...

journal article 2010