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Magnetically tunable supercurrent in dilute magnetic topological insulator-based Josephson junctionsMandal, Pankaj (author), Mondal, Soumi (author), Stehno, Martin P. (author), Ilić, Stefan (author), Bergeret, F. Sebastian (author), Klapwijk, T.M. (author), Gould, Charles (author), Molenkamp, Laurens W. (author)A superconductor, when exposed to a spin-exchange field, can exhibit spatial modulation of its order parameter, commonly referred to as the Fulde–Ferrell–Larkin–Ovchinnikov state. Such a state can be induced by controlling the spin-splitting field in Josephson junction devices, allowing access to a wide range of the phase diagram. Here we...journal article 2024
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Breunig, Daniel (author), Zhang, Song Bo (author), Trauzettel, Björn (author), Klapwijk, T.M. (author)We evaluate the microscopically relevant parameters for electrical transport of hybrid superconductor-semiconductor interfaces. In contrast to the commonly used geometrically constricted metallic systems, we focus on materials with dissimilar electronic properties like low-carrier density semiconductors combined with superconductors, without...journal article 2021
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Westig, M.P. (author), Thierschmann, R. (author), Katan, A.J. (author), Finkel, M. (author), Klapwijk, T.M. (author)We experimentally study the free-space electromagnetic field emitted from a multimode rectangular waveguide equipped with a diagonal-horn antenna. Using the frequency range of 215-580 GHz, a photomixer is used to launch a free-space circularly polarized electromagnetic field, exciting multiple modes at the input of the rectangular waveguide...journal article 2021
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Sacépé, Benjamin (author), Feigel’man, Mikhail (author), Klapwijk, T.M. (author)In order to understand the emergence of superconductivity it is useful to study the reverse process and identify the various pathways that lead to its destruction. One way is to increase the amount of disorder, as this leads to an increase in Coulomb repulsion that overpowers the attractive interaction responsible for Cooper pair formation. A...review 2020
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Westig, M.P. (author), Thierschmann, R. (author), Katan, A.J. (author), Finkel, M. (author), Klapwijk, T.M. (author)We study experimentally the transmission of an electromagnetic waveguide in the frequency range from 160 to 300 GHz. Photo-mixing is used to excite and detect the fundamental TE<sub>10</sub> mode in a rectangular waveguide with two orders-of-magnitude lower impedance. The large impedance mismatch leads to a strong frequency dependence of the...journal article 2020
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Thierschmann, R. (author), Çetinay Iyicil, H. (author), Finkel, M. (author), Katan, A.J. (author), Westig, M.P. (author), Van Mieghem, P.F.A. (author), Klapwijk, T.M. (author)We study the electrodynamic impedance of percolating conductors with a predefined network topology using a scanning microwave impedance microscope at gigahertz frequencies. For a given percolation number we observe strong spatial variations across a sample that correlate with the connected regions (clusters) in the network when the...journal article 2020
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Baselmans, J.J.A. (author), Bosma, S. (author), Ikarashi, S. (author), Klapwijk, T.M. (author), Llombart, Nuria (author), Pascual Laguna, A. (author), Thoen, David (author), de Visser, P.J. (author), Yurduseven, O. (author), Endo, A. (author)We are developing an ultra-wideband spectroscopic instrument, DESHIMA (DEep Spectroscopic HIgh-redshift MApper), based on the technologies of an on-chip filter bank and microwave kinetic inductance detector (MKID) to investigate dusty starburst galaxies in the distant universe at millimeter and submillimeter wavelengths. An on-site experiment of...journal article 2020
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Klapwijk, T.M. (author), de Visser, P.J. (author)We trace the historical fate of experiment and theory of microwave-stimulated superconductivity as originally reported for constriction-type superconducting weak links. It is shown that the observed effect disappeared by improving weak links to obtain the desired Josephson properties. Separate experiments were carried out to evaluate the...journal article 2020
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Semenov, A. V. (author), Devyatov, I. A. (author), Westig, M.P. (author), Klapwijk, T.M. (author)We address parametric amplifiers and kinetic inductance detectors, using concepts of the microscopic theory of superconductivity, and focusing on the interaction of microwave radiation with the superconducting condensate. This interaction was identified in recent experiments as the source of the apparent dissipation in microwave...journal article 2020
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Finkel, M. (author), Thierschmann, R. (author), Katan, A.J. (author), Westig, M.P. (author), Spirito, M. (author), Klapwijk, T.M. (author)We have realized a microstrip based terahertz (THz) near field cantilever that enables quantitative measurements of the impedance of the probe tip at THz frequencies (0.3 THz). A key feature is the on-chip balanced hybrid coupler that serves as an interferometer for passive signal cancellation to increase the readout circuit sensitivity...journal article 2019
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Endo, A. (author), Karatsu, K. (author), Pascual Laguna, A. (author), Mirzaei, B. (author), Thoen, David (author), van Marrewijk, N.T. (author), Bosma, S. (author), Yurduseven, O. (author), Llombart, Nuria (author), Klapwijk, T.M. (author), Baselmans, J.J.A. (author)Terahertz spectrometers with a wide instantaneous frequency coverage for passive remote sensing are enormously attractive for many terahertz applications, such as astronomy, atmospheric science, and security. Here we demonstrate a wide-band terahertz spectrometer based on a single superconducting chip. The chip consists of an antenna coupled...journal article 2019
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Endo, A. (author), Karatsu, K. (author), Bosma, S. (author), Ikarashi, S. (author), Klapwijk, T.M. (author), Llombart, Nuria (author), Pascual Laguna, A. (author), Thoen, David (author), de Visser, P.J. (author), Yurduseven, O. (author), Baselmans, J.J.A. (author)Ultra-wideband, three-dimensional (3D) imaging spectrometry in the millimeter–submillimeter (mm–submm) band is an essential tool for uncovering the dust-enshrouded portion of the cosmic history of star formation and galaxy evolution<sup>1–3</sup>. However, it is challenging to scale up conventional coherent heterodyne receivers<sup>4</sup> or...journal article 2019
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Vodolazov, D. Yu (author), Klapwijk, T.M. (author)We study, theoretically, the single-photon response of a strongly disordered thin superconducting strip in the flux flow state. We find that this resistive state, at a current I larger than the critical current Ic, jumps to the normal state by the absorption of a single optical photon. The absorbed photon creates a beltlike region with...journal article 2019
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Thierschmann, R. (author), Mulazimoglu, E. (author), Manca, N. (author), Goswami, S. (author), Klapwijk, T.M. (author), Caviglia, A. (author)One of the hallmark experiments of quantum transport is the observation of the quantized resistance in a point contact in GaAs/AlGaAs heterostructures. Being formed with split gate technology, these structures represent in an ideal manner equilibrium reservoirs which are connected only through a few electron mode channel. It has been a long...journal article 2018
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Tikhonov, K. S. (author), Skvortsov, M. A. (author), Klapwijk, T.M. (author)We address the problem of nonequilibrium superconductivity in the presence of microwave irradiation. Using contemporary analytical methods, we refine the old Eliashberg theory and generalize it to arbitrary temperatures T and frequencies ω. Microwave radiation is shown to stimulate superconductivity in a bounded region in the (ω,T) plane. In...journal article 2018
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Peltonen, J. T. (author), Coumou, P.C.J.J. (author), Peng, Z. (author), Klapwijk, T.M. (author), Tsai, J. S. (author), Astafiev, O. V. (author)We report development and microwave characterization of rf SQUID (Superconducting QUantum Interference Device) qubits, consisting of an aluminium-based Josephson junction embedded in a superconducting loop patterned from a thin film of TiN with high kinetic inductance. Here we demonstrate that the systems can offer small physical size, high...journal article 2018
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Baeva, E. M. (author), Sidorova, M. V. (author), Korneev, A. A. (author), Smirnov, K. V. (author), Divochy, A. V. (author), Morozov, P. V. (author), Zolotov, P. I. (author), Vakhtomin, Yu B. (author), Klapwijk, T.M. (author)We investigate thermal properties of a NbN single-photon detector capable of unit internal detection efficiency. Using an independent calibration of the coupling losses, we determine the absolute optical power absorbed by the NbN film and, via resistive superconductor thermometry, the temperature dependence of the thermal resistance Z(T) of...journal article 2018
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Korneeva, Yuliya (author), Vodolazov, Denis (author), Florya, Irina (author), Manova, Nadegda (author), Smirnov, Eugenii (author), Korneev, Alexander (author), Mikhailov, Michail (author), Goltsman, Gregory (author), Klapwijk, T.M. (author)We experimentally demonstrate the single photon detection in straight micrometer-wide NbN and α-MoSi bridges. Width of the bridges is 2 μm, while the wavelength of the photon changes from 408 to 1550 nm and critical current exceeds 50% of the depairing current. Obtained results offer the alternative route for design of detectors without...journal article 2018
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Westig, M.P. (author), Klapwijk, T.M. (author)A directional superconducting parametric amplifier in the GHz frequency range is designed and analyzed, suitable for low-power read-out of microwave kinetic inductance detectors employed in astrophysics and when combined with a nonreciprocal device at its input also for circuit quantum electrodynamics. It consists of a one-wavelength-long...journal article 2018
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Klapwijk, T.M. (author), Semenov, A. V. (author)Superconducting hot-electron bolometers are presently the best performing mixing devices for the frequency range beyond 1.2 THz, where good-quality superconductor-insulator-superconductor devices do not exist. Their physical appearance is very simple: an antenna consisting of a normal metal, sometimes a normal-metal-superconductor bilayer,...journal article 2017