- document
-
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 chain<sup>1</sup>. Practical proposals for its realization<sup>2,3</sup> require coupling neighbouring...journal article 2023
- document
-
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
- document
-
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
- document
-
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
- document
-
Kroll, J. (author), Uilhoorn, W. (author), van der Enden, K.L. (author), de Jong, D. (author), Watanabe, K. (author), Taniguchi, T. (author), Goswami, S. (author), Cassidy, M.C. (author), Kouwenhoven, Leo P. (author)Circuit quantum electrodynamics has proven to be a powerful tool to probe mesoscopic effects in hybrid systems and is used in several quantum computing (QC) proposals that require a transmon qubit able to operate in strong magnetic fields. To address this we integrate monolayer graphene Josephson junctions into microwave frequency...journal article 2018
- document
-
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
- document
-
Laird, E.A. (author), Kuemmeth, F. (author), Steele, G.A. (author), Grove-Rasmussen, K. (author), Nygard, J. (author), Flensberg, K. (author), Kouwenhoven, L.P. (author)Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin and valley degrees of freedom. This review describes the modern understanding of...journal article 2015
- document
-
Qu, F. (author), Beukman, A.J.A. (author), Nadj-Perge, S. (author), Wimmer, M.T. (author), Nguyen, B.M. (author), Yi, W. (author), Thorp, J. (author), Sokolich, M. (author), Kiselev, A.A. (author), Manfra, M.J. (author), Marcus, C.M. (author), Kouwenhoven, L.P. (author)Among the theoretically predicted two-dimensional topological insulators, InAs/GaSb double quantum wells (DQWs) have a unique double-layered structure with electron and hole gases separated in two layers, which enables tuning of the band alignment via electric and magnetic fields. However, the rich trivial-topological phase diagram has yet to be...journal article 2015
- document
-
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
- document
-
Yi, W. (author), Kiselev, A.A. (author), Thorp, J. (author), Noah, R. (author), Nguyen, B.M. (author), Bui, S. (author), Rajavel, R.D. (author), Hussain, T. (author), Gyure, M.F. (author), Kratz, P. (author), Qian, Q. (author), Manfra, M.J. (author), Pribiag, V.S. (author), Kouwenhoven, L.P. (author), Marcus, C.M. (author), Sokolich, M. (author)Gate-tunable high-mobility InSb/In1?xAlxSb quantum wells (QWs) grown on GaAs substrates are reported. The QW two-dimensional electron gas (2DEG) channel mobility in excess of 200?000?cm2/V?s is measured at T?=?1.8?K. In asymmetrically remote-doped samples with an HfO2 gate dielectric formed by atomic layer deposition, parallel conduction is...journal article 2015
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
Recher, P. (author), Nazarov, Y.V. (author), Kouwenhoven, L.P. (author)We consider an optical quantum dot where an electron level and a hole level are coupled to respective superconducting leads. We find that electrons and holes recombine producing photons at discrete energies as well as a continuous tail. Further, the spectral lines directly probe the induced superconducting correlations on the dot. At energies...journal article 2010
- document
-
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
- document
-
Akopian, N. (author), Van Weert, M. (author), Van Kouwen, M. (author), Algra, R. (author), Liu, L. (author), Patriarche, G. (author), Harmand, J.C. (author), Bakkers, E. (author), Kouwenhoven, L. (author), Zwiller, V. (author)In this paper we present our recent developments in control and manipulation of individual spins and photons in a single nanowire quantum dot. Specific examples include demonstration of optical excitation of single spin states, charge tunable quantum devices and single photon sources. We will also discuss our recent discovery of a new type of...conference paper 2010