- document
-
Kouwenhoven, K. (author), Elwakil, I. (author), van Wingerden, J. (author), Murugesan, V. (author), Thoen, David (author), Baselmans, J.J.A. (author), de Visser, P.J. (author)Typical materials for optical Microwave Kinetic Inductance Detetectors (MKIDs) are metals with a natural absorption of ∼ 30–50% in the visible and near-infrared. To reach high absorption efficiencies (90–100%) the KID must be embedded in an optical stack. We show an optical stack design for a 60 nm TiN film. The optical stack is modeled as...journal article 2022
- document
-
Mazur, G.P. (author), van Loo, N. (author), Wang, J. (author), Dvir, T. (author), Wang, Guanzhong (author), Korneychuk, S. (author), Borsoi, F. (author), Dekker, R.C. (author), Badawy, G.H.A. (author), Vinke, Peter (author), Quintero Perez, M. (author), Heedt, S. (author), Kouwenhoven, Leo P. (author)In superconducting quantum circuits, aluminum is one of the most widely used materials. It is currently also the superconductor of choice for the development of topological qubits. However, aluminum-based devices suffer from poor magnetic field compatibility. Herein, this limitation is resolved by showing that adatoms of heavy elements (e.g.,...journal article 2022
- document
-
Wang, Guanzhong (author), Dvir, T. (author), Mazur, G.P. (author), Liu, C. (author), van Loo, N. (author), ten Haaf, S.L.D. (author), Bordin, A. (author), Gazibegovic, Sasa (author), Badawy, G.H.A. (author), Bakkers, Erik P.A.M. (author), Wimmer, M.T. (author), Kouwenhoven, Leo P. (author)In most naturally occurring superconductors, electrons with opposite spins form Cooper pairs. This includes both conventional s-wave superconductors such as aluminium, as well as high-transition-temperature, d-wave superconductors. Materials with intrinsic p-wave superconductivity, hosting Cooper pairs made of equal-spin electrons, have not...journal article 2022
- document
-
Wang, Ji Yin (author), van Loo, N. (author), Mazur, G.P. (author), Levajac, V. (author), Malinowski, F.K. (author), Lemang, M.F. (author), Borsoi, F. (author), Badawy, G.H.A. (author), Quintero Perez, M. (author), Heedt, S. (author), Kouwenhoven, Leo P. (author)We systematically study three-terminal InSb-Al nanowire devices by using radio-frequency reflectometry. Tunneling spectroscopy measurements on both ends of the hybrid nanowires are performed while systematically varying the chemical potential, magnetic field, and junction transparencies. Identifying the lowest-energy state allows for the...journal article 2022
- document
-
WANG, J. (author), Schrade, Constantin (author), Levajac, V. (author), van Driel, D. (author), Li, K. (author), Badawy, G.H.A. (author), Lee, J.S. (author), Kouwenhoven, Leo P. (author), Shen, Jie (author)We study a Cooper pair transistor realized by two Josephson weak links that enclose a superconducting island in an InSb-Al hybrid nanowire. When the nanowire is subject to a magnetic field, isolated subgap levels arise in the superconducting island and, because of the Coulomb blockade, mediate a supercurrent by coherent cotunneling of Cooper...journal article 2022
- document
-
Bargerbos, A. (author), Pita-Vidal, Marta (author), Splitthoff, L.J. (author), Grünhaupt, L. (author), Wesdorp, J.J. (author), Andersen, C.K. (author), Liu, Yu (author), Kouwenhoven, Leo P. (author), van Heck, B. (author)We realize a hybrid superconductor-semiconductor transmon device in which the Josephson effect is controlled by a gate-defined quantum dot in an InAs-Al nanowire. Microwave spectroscopy of the transition spectrum of the transmon allows us to probe the ground-state parity of the quantum dot as a function of the gate voltages, the external...journal article 2022
- document
-
Wang, Guanzhong (author), Dvir, T. (author), van Loo, N. (author), Mazur, G.P. (author), Gazibegovic, Sasa (author), Badawy, G.H.A. (author), Bakkers, Erik P.A.M. (author), Kouwenhoven, Leo P. (author), de Lange, G. (author)The lowest-energy excitations of superconductors do not carry an electric charge, as their wave function is equally electron-like and hole-like. This fundamental property is not easy to study in electrical measurements that rely on the charge to generate an observable signal. The ability of a quantum dot to act as a charge filter enables us...journal article 2022
- document
-
Malinowski, F.K. (author), Han, L. (author), de Jong, D. (author), Wang, Ji Yin (author), Prosko, C.G. (author), Krogstrup, Peter (author), Bakkers, Erik P.A.M. (author), Kouwenhoven, Leo P. (author), Koski, Jonne V. (author)We demonstrate the use of radio-frequency (rf) resonators to measure the capacitance of nanoscale semiconducting devices in field-effect transistor configurations. The rf resonator is attached to the gate or the lead of the device. Consequently, tuning the carrier density in the conducting channel of the device affects the resonance frequency...journal article 2022
- document
-
Buijtendorp, B.T. (author), Vollebregt, S. (author), Karatsu, K. (author), Thoen, David (author), Murugesan, V. (author), Kouwenhoven, K. (author), Hähnle, S.A. (author), Baselmans, J.J.A. (author), Endo, A. (author)Low-loss deposited dielectrics will benefit superconducting devices such as integrated superconducting spectrometers, superconducting qubits, and kinetic inductance parametric amplifiers. Compared with planar structures, multilayer structures such as microstrips are more compact and eliminate radiation loss at high frequencies. Multilayer...journal article 2022
- document
-
op het Veld, R.L.M. (author), Xu, D. (author), Schaller, V. (author), Wang, Q. (author), de Moor, M.W.A. (author), Hesselmann, Bart (author), Vermeulen, K.J. (author), Bommer, J.D.S. (author), Kouwenhoven, Leo P. (author), Zhang, H. (author)The Data availability statement of this article has been modified to add the accession link to the raw data. The old Data availability statement read “Materials and data that support the findings of this research are available within the paper. All data are available from the corresponding author upon request”. This has been replaced by ...journal article 2021
- document
-
Borsoi, F. (author), Mazur, G.P. (author), van Loo, N. (author), Bourdet, L.R. (author), Li, K. (author), Fursina, A. (author), Wang, J. (author), Levajac, V. (author), Memisevic, E. (author), van Hoogdalem, K.A. (author), Kouwenhoven, Leo P. (author), Heedt, S. (author), Quintero Perez, M. (author)Semiconducting–superconducting hybrids are vital components for the realization of high-performance nanoscale devices. In particular, semiconducting–superconducting nanowires attract widespread interest owing to the possible presence of non-abelian Majorana zero modes, which are quasiparticles that hold promise for topological quantum...journal article 2021
- document
-
Shen, J. (author), Winkler, G. W. (author), Borsoi, F. (author), Heedt, S. (author), Levajac, V. (author), Wang, J. (author), van Driel, D. (author), Bouman, D. (author), Kouwenhoven, Leo P. (author), van Heck, B. (author)We measure the charge periodicity of Coulomb blockade conductance oscillations of a hybrid InSb-Al island as a function of gate voltage and parallel magnetic field. The periodicity changes from to at a gate-dependent value of the magnetic field, , decreasing from a high to a low limit upon increasing the gate voltage. In the gate voltage...journal article 2021
- document
-
Heedt, S. (author), Quintero Perez, M. (author), Borsoi, F. (author), van Loo, N. (author), Mazur, G.P. (author), Ammerlaan, M.L.I. (author), Li, K. (author), Korneychuk, S. (author), van de Poll, M.A.Y. (author), de Jong, N. (author), Aseev, P. (author), van Hoogdalem, K.A. (author), Kouwenhoven, Leo P. (author)The realization of hybrid superconductor–semiconductor quantum devices, in particular a topological qubit, calls for advanced techniques to readily and reproducibly engineer induced superconductivity in semiconductor nanowires. Here, we introduce an on-chip fabrication paradigm based on shadow walls that offers substantial advances in device...journal article 2021
- document
-
Hähnle, S.A. (author), Kouwenhoven, K. (author), Buijtendorp, B.T. (author), Endo, A. (author), Karatsu, K. (author), Thoen, David (author), Murugesan, V. (author), Baselmans, J.J.A. (author)We present a lab-on-chip experiment to accurately measure losses of superconducting microstrip lines at microwave and submillimeter wavelengths. The microstrips are fabricated from Nb-Ti-N, which is deposited using reactive magnetron sputtering, and amorphous silicon which is deposited using plasma-enhanced chemical vapor deposition (PECVD)....journal article 2021
- document
-
de Jong, D. (author), Prosko, C.G. (author), Waardenburg, D.M.A. (author), Han, L. (author), Malinowski, F.K. (author), Krogstrup, P. (author), Kouwenhoven, Leo P. (author), Koski, J.V. (author), Pfaff, W. (author)Superconducting resonators enable fast characterization and readout of mesoscopic quantum devices. Finding ways to perform measurements of interest on such devices using resonators only is therefore of great practical relevance. We report an experimental investigation of an InAs nanowire multiquantum dot device by probing gigahertz resonators...journal article 2021
- document
-
de Jong, Gerard (author), Kouwenhoven, M.L.A. (author), Daly, Andrew (author), Thoen, S. (author), de Gier, Matthijs (author), Hofman, Frank (author)Time-of-day (TOD) choice can be considered as a fifth stage in the modelling of transport behaviour, additional to the conventional four stages. Twenty years ago in The Netherlands, a stated preference (SP) study was designed for investigating the choice of time-of-day (departure time) and transport mode. A nested logit time period and mode...journal article 2020
- document
-
op het Veld, R.L.M. (author), Xu, D. (author), Schaller, V. (author), Wang, Q. (author), de Moor, M.W.A. (author), Vermeulen, K.J. (author), Bommer, J.D.S. (author), Kouwenhoven, Leo P. (author), Zhang, H. (author)Strong spin–orbit semiconductor nanowires coupled to a superconductor are predicted to host Majorana zero modes. Exchange (braiding) operations of Majorana modes form the logical gates of a topological quantum computer and require a network of nanowires. Here, we utilize an in-plane selective area growth technique for InSb–Al semiconductor...journal article 2020
- document
-
Bargerbos, A. (author), Uilhoorn, W. (author), Yang, C. (author), Krogstrup, Peter (author), Kouwenhoven, Leo P. (author), de Lange, G. (author), van Heck, B. (author), Kou, A. (author)Isolation from the environment determines the extent to which charge is confined on an island, which manifests as Coulomb oscillations, such as charge dispersion. We investigate the charge dispersion of a nanowire transmon hosting a quantum dot in the junction. We observe rapid suppression of the charge dispersion with increasing junction...journal article 2020
- document
-
Borsoi, F. (author), Zuo, Kun (author), Gazibegovic, Sasa (author), op het Veld, R.L.M. (author), Bakkers, Erik P.A.M. (author), Kouwenhoven, Leo P. (author), Heedt, S. (author)Detecting the transmission phase of a quantum dot via interferometry can reveal the symmetry of the orbitals and details of electron transport. Crucially, interferometry will enable the read-out of topological qubits based on one-dimensional nanowires. However, measuring the transmission phase of a quantum dot in a nanowire has not yet been...journal article 2020
- document
-
van Cranenburgh, S. (author), Kouwenhoven, M.L.A. (author)This study proposes a novel Artificial Neural Network (ANN) based method to derive the Value-of-Travel-Time (VTT) distribution. The strength of this method is that it is possible to uncover the VTT distribution (and its moments) without making assumptions about the shape of the distribution or the error terms, while being able to incorporate...journal article 2020