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Hsiao, T. (author), Cova Fariña, P. (author), Oosterhout, S.D. (author), Jirovec, D. (author), Zhang, X. (author), van Diepen, C.J. (author), Lawrie, W.I.L. (author), Wang, C.A. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L.M.K. (author)Quantum systems with engineered Hamiltonians can be used to study many-body physics problems to provide insights beyond the capabilities of classical computers. Semiconductor gate-defined quantum dot arrays have emerged as a versatile platform for realizing generalized Fermi-Hubbard physics, one of the richest playgrounds in condensed matter...journal article 2024
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Prabowo, B. (author), Pietx i Casas, O. (author), Montazerolghaem, M.A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author), Sebastiano, F. (author), Babaie, M. (author)Continuous rounds of quantum error correction (QEC) are essential to achieve faulttolerant quantum computers (QCs). In each QEC cycle, thousands of ancilla quantum bits (qubits) must be read out faster than the qubits' decoherence time (<<T2∗~120μs for spin qubits). To address this urgent need, several CMOS receivers operating at...conference paper 2024
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Degli Esposti, D. (author), Stehouwer, L.E.A. (author), Gül, Önder (author), Samkharadze, Nodar (author), Déprez, C.C. (author), Meyer, M. (author), Meijer, Ilja N. (author), Tryputen, L. (author), Karwal, S. (author), Vandersypen, L.M.K. (author), Sammak, A. (author), Veldhorst, M. (author), Scappucci, G. (author)The electrical characterisation of classical and quantum devices is a critical step in the development cycle of heterogeneous material stacks for semiconductor spin qubits. In the case of silicon, properties such as disorder and energy separation of conduction band valleys are commonly investigated individually upon modifications in selected...journal article 2024
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Paquelet Wuetz, B. (author), Degli Esposti, D. (author), Zwerver, A.M.J. (author), Amitonov, S. (author), Botifoll, Marc (author), Arbiol, Jordi (author), Sammak, A. (author), Vandersypen, L.M.K. (author), Russ, M.F. (author), Scappucci, G. (author)Charge noise in the host semiconductor degrades the performance of spin-qubits and poses an obstacle to control large quantum processors. However, it is challenging to engineer the heterogeneous material stack of gate-defined quantum dots to improve charge noise systematically. Here, we address the semiconductor-dielectric interface and the...journal article 2023
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Bonsen, T.R. (author), Harvey-Collard, P. (author), Russ, M.F. (author), Dijkema, J.J. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)We report observations of transitions between excited states in the Jaynes-Cummings ladder of circuit quantum electrodynamics with electron spins (spin circuit QED). We show that unexplained features in recent experimental work correspond to such transitions and present an input-output framework that includes these effects. In new experiments...journal article 2023
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Undseth, B.W. (author), Pietx i Casas, O. (author), Raymenants, E.R. (author), Mehmandoost, M. (author), Madzik, M.T. (author), Philips, S.G.J. (author), de Snoo, S.L. (author), Michalak, D.J. (author), Amitonov, S. (author), Tryputen, L. (author), Paquelet Wuetz, B. (author), Fezzi, V. (author), Degli Esposti, D. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)As spin-based quantum processors grow in size and complexity, maintaining high fidelities and minimizing crosstalk will be essential for the successful implementation of quantum algorithms and error-correction protocols. In particular, recent experiments have highlighted pernicious transient qubit frequency shifts associated with microwave...journal article 2023
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Undseth, B.W. (author), Xue, X. (author), Mehmandoost, M. (author), Rimbach-Russ, Maximilian (author), Eendebak, P.T. (author), Samkharadze, Nodar (author), Sammak, A. (author), Dobrovitski, V.V. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)Micromagnet-based electric dipole spin resonance offers an attractive path for the near-term scaling of dense arrays of silicon spin qubits in gate-defined quantum dots while maintaining long coherence times and high control fidelities. However, accurately controlling dense arrays of qubits using a multiplexed drive will require an...journal article 2023
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Zwerver, A.M.J. (author), Amitonov, S. (author), de Snoo, S.L. (author), Madzik, M.T. (author), Russ, M.F. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)Coherent links between qubits separated by tens of micrometers are expected to facilitate scalable quantum computing architectures for spin qubits in electrically defined quantum dots. These links create space for classical on-chip control electronics between qubit arrays, which can help to alleviate the so-called wiring bottleneck. A...journal article 2023
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Russ, M.F. (author), Philips, S.G.J. (author), Xue, X. (author), Vandersypen, L.M.K. (author)Semiconductor spin qubits demonstrated single-qubit gates with fidelities up to 99.9 % benchmarked in the single-qubit subspace. However, tomographic characterizations reveal non-negligible crosstalk errors in a larger space. Additionally, it was long thought that the two-qubit gate performance is limited by charge noise, which couples to the...journal article 2023
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Unseld, F.K. (author), Meyer, M. (author), Madzik, M.T. (author), Borsoi, F. (author), de Snoo, S.L. (author), Amitonov, S. (author), Sammak, A. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L.M.K. (author)Semiconductor spin qubits have gained increasing attention as a possible platform to host a fault-tolerant quantum computer. First demonstrations of spin qubit arrays have been shown in a wide variety of semiconductor materials. The highest performance for spin qubit logic has been realized in silicon, but scaling silicon quantum dot arrays...journal article 2023
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Meyer, M. (author), Déprez, C.C. (author), Meijer, Ilja N. (author), Unseld, F.K. (author), Karwal, S. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author), Veldhorst, M. (author)The small footprint of semiconductor qubits is favorable for scalable quantum computing. However, their size also makes them sensitive to their local environment and variations in the gate structure. Currently, each device requires tailored gate voltages to confine a single charge per quantum dot, clearly challenging scalability. Here, we...journal article 2023
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Philips, S.G.J. (author), Madzik, M.T. (author), Amitonov, S. (author), de Snoo, S.L. (author), Russ, M.F. (author), Kalhor, N. (author), Volk, C.A. (author), Lawrie, W.I.L. (author), Brousse, D. (author), Tryputen, L. (author), Paquelet Wuetz, B. (author), Sammak, A. (author), Veldhorst, M. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)Future quantum computers capable of solving relevant problems will require a large number of qubits that can be operated reliably1. However, the requirements of having a large qubit count and operating with high fidelity are typically conflicting. Spins in semiconductor quantum dots show long-term promise2,3 but demonstrations so far use...journal article 2022
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Xue, X. (author), Russ, M.F. (author), Samkharadze, Nodar (author), Undseth, B.W. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)High-fidelity control of quantum bits is paramount for the reliable execution of quantum algorithms and for achieving fault tolerance—the ability to correct errors faster than they occur<sup>1</sup>. The central requirement for fault tolerance is expressed in terms of an error threshold. Whereas the actual threshold depends on many details, a...journal article 2022
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Harvey-Collard, P. (author), Dijkema, J.J. (author), Zheng, G. (author), Sammak, A. (author), Scappucci, G. (author), Vandersypen, L.M.K. (author)We report the coherent coupling of two electron spins at a distance via virtual microwave photons. Each spin is trapped in a silicon double quantum dot at either end of a superconducting resonator, achieving spin-photon couplings up to around gs/2p=40 MHz. As the two spins are brought into resonance with each other, but detuned from the...journal article 2022
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Petit, L. (author), Russ, M.F. (author), Eenink, H.G.J. (author), Lawrie, W.I.L. (author), Clarke, James S. (author), Vandersypen, L.M.K. (author), Veldhorst, M. (author)Spin qubits in quantum dots define an attractive platform for quantum information because of their compatibility with semiconductor manufacturing, their long coherence times, and the ability to operate above one Kelvin. However, despite demonstrations of SWAP oscillations, the integration of this two-qubit gate together with single-qubit...journal article 2022
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Pellerano, Stefano (author), Subramanian, Sushil (author), Park, Jong-Seok (author), Patra, Bishnu (author), Xue, X. (author), Vandersypen, L.M.K. (author), Babaie, M. (author), Charbon-Iwasaki-Charbon, E. (author), Sebastiano, F. (author)Quantum computers have been heralded as a novel paradigm for the solution of today's intractable problems, whereas the core principles of quantum computation are superposition, entanglement and interference, three fundamental properties of quantum mechanics [1]. A quantum computer generally comprises a quantum processor, made of an array of...conference paper 2022
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Vandersypen, L.M.K. (author)Quantum computation has captivated the minds of many for almost two decades. For much of that time, it was seen mostly as an extremely interesting scientific problem. In the last few years, we have entered a new phase as the belief has grown that a large-scale quantum computer can actually be built. Quantum bits encoded in the spin state of...conference paper 2022
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Knörzer, J. (author), van Diepen, C.J. (author), Hsiao, T. (author), Giedke, G. (author), Mukhopadhyay, U. (author), Reichl, C. (author), Wegscheider, W. (author), Cirac, J. I. (author), Vandersypen, L.M.K. (author)Long-range interactions play a key role in several phenomena of quantum physics and chemistry. To study these phenomena, analog quantum simulators provide an appealing alternative to classical numerical methods. Gate-defined quantum dots have been established as a platform for quantum simulation, but for those experiments the effect of long...journal article 2022
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Zwerver, A.M.J. (author), Krähenmann, T.S. (author), Amitonov, S. (author), Boter, J.M. (author), Droulers, G. (author), Lodari, M. (author), Samkharadze, Nodar (author), Zheng, G. (author), Scappucci, G. (author), Veldhorst, M. (author), Vandersypen, L.M.K. (author)Full-scale quantum computers require the integration of millions of qubits, and the potential of using industrial semiconductor manufacturing to meet this need has driven the development of quantum computing in silicon quantum dots. However, fabrication has so far relied on electron-beam lithography and, with a few exceptions, conventional...journal article 2022
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Boter, J.M. (author), Dehollain Lorenzana, J.P. (author), van Dijk, J.P.G. (author), Xu, Yuanxing (author), Hensgens, T. (author), Versluis, R. (author), Naus, H.W.L. (author), Veldhorst, M. (author), Sebastiano, F. (author), Vandersypen, L.M.K. (author)One of the main bottlenecks in the pursuit of a large-scale-chip-based quantum computer is the large number of control signals needed to operate qubit systems. As system sizes scale up, the number of terminals required to connect to off-chip control electronics quickly becomes unmanageable. Here, we discuss a quantum-dot spin-qubit...journal article 2022