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van Riggelen, F (author), Hendrickx, N.W. (author), Lawrie, W.I.L. (author), Russ, M. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author)Quantum dots fabricated using techniques and materials that are compatible with semiconductor manufacturing are promising for quantum information processing. While great progress has been made toward high-fidelity control of quantum dots positioned in a linear arrangement, scalability along two dimensions is a key step toward practical quantum...conference paper 2021
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Aggarwal, K. (author), Hofmann, A. (author), Jirovec, D. (author), Prieto, I. (author), Sammak, A. (author), Botifoll, M. (author), Martí-Sánchez, S. (author), Veldhorst, M. (author), Arbiol, J. (author), Scappucci, G. (author), Danon, J. (author), Katsaros, G. (author)Hole gases in planar germanium can have high mobilities in combination with strong spin-orbit interaction and electrically tunable g factors, and are therefore emerging as a promising platform for creating hybrid superconductor-semiconductor devices. A key challenge towards hybrid Ge-based quantum technologies is the design of high-quality...article 2021
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Lawrie, W.I.L. (author), Eenink, H.G.J. (author), Hendrickx, N.W. (author), Boter, J.M. (author), Petit, L. (author), Amitonov, S.V. (author), Lodari, M. (author), paquelet Wuetz, B. (author), Volk, C. (author), Philips, S.G.J. (author), Droulers, G. (author), Kalhor, N. (author), van Riggelen, F. (author), Brousse, D. (author), Sammak, A. (author), Vandersypen, L.M.K. (author), Scappucci, G. (author), Veldhorst, M. (author)Electrons and holes confined in quantum dots define excellent building blocks for quantum emergence, simulation, and computation. Silicon and germanium are compatible with standard semiconductor manufacturing and contain stable isotopes with zero nuclear spin, thereby serving as excellent hosts for spins with long quantum coherence. Here, we...article 2020
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Last, T. (author), Samkharadze, N. (author), Eendebak, P.T. (author), Versluis, R. (author), Xue, X. (author), Sammak, A. (author), Brousse, D. (author), Loh, K.K.L. (author), Polinder, H. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L. (author), Maturová, K. (author), Veltin, J. (author), Alberts, G.J.N. (author)The mission of QuTech is to bring quantum technology to industry and society by translating fundamental scientific research into applied research. To this end we are developing Quantum Inspire (QI), a full-stack quantum computer prototype for future co-development and collaborative R&D in quantum computing. A prerelease of this prototype system...conference paper 2020
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Xu, Y. (author), Unseld, F.K. (author), Corna, A. (author), Zwerver, A.M.J. (author), Sammak, A. (author), Brousse, D. (author), Samkharadze, N. (author), Amitonov, S.V. (author), Veldhorst, M. (author), Scappucci, G. (author), Ishihara, R. (author), Vandersypen, L.M.K. (author)Solid-state qubits integrated on semiconductor substrates currently require at least one wire from every qubit to the control electronics, leading to a so-called wiring bottleneck for scaling. Demultiplexing via on-chip circuitry offers an effective strategy to overcome this bottleneck. In the case of gate-defined quantum dot arrays, specific...article 2020
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Harvey-Collard, P. (author), Zheng, G. (author), Dijkema, J. (author), Samkharadze, N. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)Circuit quantum electrodynamics (QED) employs superconducting microwave resonators as quantum buses. In circuit QED with semiconductor quantum-dot-based qubits, increasing the resonator impedance is desirable as it enhances the coupling to the typically small charge dipole moment of these qubits. However, the gate electrodes necessary to form...article 2020
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Hendrickx, N.W. (author), Franke, D.P. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author)Universal quantum information processing requires the execution of single-qubit and two-qubit logic. Across all qubit realizations1, spin qubits in quantum dots have great promise to become the central building block for quantum computation2. Excellent quantum dot control can be achieved in gallium arsenide3–5, and high-fidelity qubit rotations...article 2020
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Del Vecchio, P. (author), Lodari, M. (author), Sammak, A. (author), Scappucci, G. (author), Moutanabbir, O. (author)A clear signature of Zeeman split states crossing is observed in a Landau fan diagram of strained germanium two-dimensional hole gas. The underlying mechanisms are discussed based on a perturbative model yielding a closed formula for the critical magnetic fields. These fields depend strongly on the energy difference between the topmost and...article 2020
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Patra, B. (author), van Dijk, J.P.G. (author), Subramanian, S. (author), Corna, A. (author), Xue, X. (author), Jeon, C. (author), Sheikh, F. (author), Juarez-Hernandez, E. (author), Esparza, B.P. (author), Rampurawala, H. (author), Carlton, B. (author), Samkharadze, N. (author), Ravikumar, S. (author), Nieva, C. (author), Kim, S. (author), Lee, H.J. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L.M.K. (author), Babaie, M. (author), Sebastiano, F. (author), Charbon, E. (author), Pellerano, S. (author)Quantum computers (QC), comprising qubits and a classical controller, can provide exponential speed-up in solving certain problems. Among solid-state qubits, transmons and spin-qubits are the most promising, operating ≪ 1K. A qubit can be implemented in a physical system with two distinct energy levels representing the |0⟩ and |1⟩ states, e.g....conference paper 2020
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Xue, X. (author), Patra, B. (author), van Dijk, J.P.G. (author), Samkharadze, N. (author), Subramanian, S. (author), Corna, A. (author), Jeon, C. (author), Sheikh, F. (author), Juarez-Hernandez, E. (author), Perez Esparza, B. (author), Rampurawala, H. (author), Varlton, B. (author), Ravikumar, S. (author), Nieva, C. (author), Kim, S. (author), Lee, H.J. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author), Sebastiano, F. (author), Babaie, M. (author), Pellerano, S. (author), Charbon, E. (author), Vandersypen, L.M.K. (author)The most promising quantum algorithms require quantum processors hosting millions of quantum bits when targeting practical applications. A major challenge towards large-scale quantum computation is the interconnect complexity. In current solid-state qubit implementations, a major bottleneck appears between the quantum chip in a dilution...conference paper 2020
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- Lodari, M. (author), Hendrickx, N.W. (author), Lawrie, W.I.L. (author), Hsiao, T.K. (author), Vandersypen, L.M.K. (author), Sammak, A. (author), Veldhorst, M. (author), Scappucci, G. (author) conference paper 2020
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Paquelet Wütz, B. (author), Losert, M.P. (author), Tosato, A. (author), Lodari, M. (author), Bavdaz, P.L. (author), Stehouwer, L. (author), Amin, P. (author), Clarke, J.S. (author), Coppersmith, S.N. (author), Sammak, A. (author), Veldhorst, M. (author), Friesen, M. (author), Scappucci, G. (author)We determine the energy splitting of the conduction-band valleys in two-dimensional electrons confined to low-disorder Si quantum wells. We probe the valley splitting dependence on both perpendicular magnetic field B and Hall density by performing activation energy measurements in the quantum Hall regime over a large range of filling factors....article 2020
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van Dijk, J.P.G. (author), Patra, B. (author), Subramanian, S. (author), Xue, X. (author), Samkharadze, N. (author), Corna, A. (author), Jeon, C. (author), Sheikh, F. (author), Juarez-Hernandez, E. (author), Perez Esparza, B. (author), Rampurawala, H. (author), Carlton, B.R. (author), Ravikumar, S. (author), Nieva, C. (author), Kim, S. (author), Lee, H.J. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L.M.K. (author), Charbon, E. (author), Pellerano, S. (author), Babaie, M. (author), Sebastiano, F. (author)Building a large-scale quantum computer requires the co-optimization of both the quantum bits (qubits) and their control electronics. By operating the CMOS control circuits at cryogenic temperatures (cryo-CMOS), and hence in close proximity to the cryogenic solid-state qubits, a compact quantumcomputing system can be achieved, thus promising...article 2020
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Lawrie, W.I.L. (author), Hendrickx, N.W. (author), van Riggelen, F. (author), Russ, M. (author), Petit, L. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author)We investigate hole spin relaxation in the single- and multihole regime in a 2 × 2 germanium quantum dot array. We find spin relaxation times T1 as high as 32 and 1.2 ms for quantum dots with single- and five-hole occupations, respectively, setting benchmarks for spin relaxation times for hole quantum dots. Furthermore, we investigate qubit...article 2020
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Zheng, G. (author), Samkharadze, N. (author), Noordam, M.L. (author), Kalhor, N. (author), Brousse, D. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)Silicon spin qubits are one of the leading platforms for quantum computation1,2. As with any qubit implementation, a crucial requirement is the ability to measure individual quantum states rapidly and with high fidelity. Since the signal from a single electron spin is minute, the different spin states are converted to different charge states3,4....article 2019
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Hendrickx, N.W. (author), Tagliaferri, M.L.V. (author), Kouwenhoven, M. (author), Li, R. (author), Franke, D.P. (author), Sammak, A. (author), Brinkman, A. (author), Scappucci, G. (author), Veldhorst, M. (author)We fabricate Josephson field-effect transistors in germanium quantum wells contacted by superconducting aluminum and demonstrate supercurrents carried by holes that extend over junction lengths of several micrometers. In superconducting quantum point contacts we observe discretization of supercurrent, as well as Fabry-Perot resonances,...article 2019
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Vigneau, F. (author), Mizokuchi, R. (author), Colao Zanuz, D. (author), Huang, X. (author), Tan, S. (author), Maurand, R. (author), Frolov, S. (author), Sammak, A. (author), Scappucci, G. (author), Lefloch, F. (author), de Franceschi, S. (author)Hybrid superconductor−semiconductor structures attract increasing attention owing to a variety of potential applications in quantum computing devices. They can serve the realization of topological superconducting systems as well as gate-tunable superconducting quantum bits. Here, we combine a SiGe/Ge/SiGe quantum-well heterostructure hosting...article 2019
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Zheng, G. (author), Samkharadze, N. (author), Noordam, M.L. (author), Kalhor, N. (author), Brousse, D. (author), Sammak, A. (author), Mendes, U.C. (author), Blais, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)We demonstrate the strong coupling between a single electron spin in silicon and a single photon in a superconducting microwave cavity. Using the same cavity we perform rapid high-fidelity single-shot readout of two-electron spin states.conference paper 2019
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Sammak, A. (author), Sabbagh, D. (author), Hendrickx, N.W. (author), Lodari, M. (author), Paquelet Wuetz, B. (author), Tosato, A. (author), Yeoh, L. (author), Bollani, M. (author), Virgilio, M. (author), Schubert, M.A. (author), Zaumseil, P. (author), Capellini, G. (author), Veldhorst, M. (author), Scappucci, G. (author)Buried-channel semiconductor heterostructures are an archetype material platform for the fabrication of gated semiconductor quantum devices. Sharp confinement potential is obtained by positioning the channel near the surface; however, nearby surface states degrade the electrical properties of the starting material. Here, a 2D hole gas of high...article 2019
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- Paquelet Wuetz, B. (author), Bavdaz, P.L. (author), Yeoh, L.A. (author), Schouten, R. (author), van der Does, H. (author), Tiggelman, M. (author), Sabbagh, D. (author), Sammak, A. (author), Almudever, C.G. (author), Sebastiano, F. (author), Clarke, J.S. (author), Veldhorst, M. (author), Scappucci, G. (author) conference paper 2019