Searched for: author:"DiCarlo, L."
(1 - 9 of 9)
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Bruno, A. (author), De Lange, G. (author), Asaad, S. (author), Van der Enden, K.L. (author), Langford, N.K. (author), DiCarlo, L. (author)
We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1?M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment prior to NbTiN deposition to optimize the metal-substrate interface and deep reactive...
journal article 2015
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De Lange, G. (author), Riste, D. (author), Tiggelman, M.J. (author), Eichler, C. (author), Tornberg, L. (author), Johansson, G. (author), Wallraff, A. (author), Schouten, R.N. (author), DiCarlo, L. (author)
We demonstrate the active suppression of transmon qubit dephasing induced by dispersive measurement, using parametric amplification and analog feedback. By real-time processing of the homodyne record, the feedback controller reverts the stochastic quantum phase kick imparted by the measurement on the qubit. The feedback operation matches a model...
journal article 2014
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Saira, O.P. (author), Groen, J.P. (author), Cramer, J. (author), Meretska, M. (author), De Lange, G. (author), DiCarlo, L. (author)
We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process tomography and successful entanglement by measurement demonstrate that the meter is...
journal article 2014
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Groen, J.P. (author), Riste, D. (author), Tornberg, L. (author), Cramer, J. (author), De Groot, P.C. (author), Picot, T. (author), Johansson, G. (author), DiCarlo, L. (author)
We realize indirect partial measurement of a transmon qubit in circuit quantum electrodynamics by interaction with an ancilla qubit and projective ancilla measurement with a dedicated readout resonator. Accurate control of the interaction and ancilla measurement basis allows tailoring the measurement strength and operator. The tradeoff between...
journal article 2013
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Riste, D. (author), Bultink, C.C. (author), Tiggelman, M.J. (author), Schouten, R.N. (author), Lehnert, K.W. (author), DiCarlo, L. (author)
The tunnelling of quasiparticles across Josephson junctions in superconducting quantum circuits is an intrinsic decoherence mechanism for qubit degrees of freedom. Understanding the limits imposed by quasiparticle tunnelling on qubit relaxation and dephasing is of theoretical and experimental interest, particularly as improved understanding of...
journal article 2013
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Ranjan, V. (author), De Lange, G. (author), Schutjens, R. (author), Debelhoir, T. (author), Groen, J.P. (author), Szombati, D. (author), Thoen, D.J. (author), Klapwijk, T.M. (author), Hanson, R. (author), DiCarlo, L. (author)
We study spin relaxation and diffusion in an electron-spin ensemble of nitrogen impurities in diamond at low temperature (0.25–1.2 K) and polarizing magnetic field (80–300 mT). Measurements exploit field-controlled coupling of the ensemble to two modes of a transmission-line resonator. The observed temperature-independent spin relaxation time...
journal article 2013
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Riste, D. (author), Bultink, C.C. (author), Lehnert, K.W. (author), DiCarlo, L. (author)
We demonstrate feedback control of a superconducting transmon qubit using discrete, projective measurement and conditional coherent driving. Feedback realizes a fast and deterministic qubit reset to a target state with 2.4% error averaged over input superposition states, and allows concatenating experiments more than 10 times faster than by...
journal article 2012
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Riste, D. (author), Van Leeuwen, J.G. (author), Ku, H.S. (author), Lehnert, K.W. (author), DiCarlo, L. (author)
We demonstrate initialization by joint measurement of two transmon qubits in 3D circuit quantum electrodynamics. Homodyne detection of cavity transmission is enhanced by Josephson parametric amplification to discriminate the two-qubit ground state from single-qubit excitations nondestructively and with 98.1% fidelity. Measurement and...
journal article 2012
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De Groot, P.C. (author), Ashhab, S. (author), Lupascu, A. (author), DiCarlo, L. (author), Nori, F. (author), Harmans, C.J.P.M. (author), Mooij, J.E. (author)
We present a theoretical analysis of the selective darkening method for implementing quantum controlled-NOT (CNOT) gates. This method, which we have recently proposed and demonstrated, consists of driving two transversely coupled quantum bits (qubits) with a driving field that is resonant with one of the two qubits. For specific relative...
journal article 2012
Searched for: author:"DiCarlo, L."
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