The Experts below are selected from a list of 13044 Experts worldwide ranked by ideXlab platform
Gopalakrishnan Balasubramanian - One of the best experts on this subject based on the ideXlab platform.
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room temperature high fidelity holonomic single Qubit Gate on a solid state spin
Nature Communications, 2014Co-Authors: Silvia Arroyocamejo, Andrii Lazariev, Stefan W Hell, Gopalakrishnan BalasubramanianAbstract:Quantum Gates based on geometric phase shifts offer a promising approach for the realization of fault-tolerant quantum computing. Using nitrogen-vacancy centre Qubits in diamond, this study experimentally realises a high-fidelty, non-adiabatic, non-Abelian holonomic single-Qubit Gate at room temperature.
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Room temperature high-fidelity holonomic single-Qubit Gate on a solid-state spin
Nature Communications, 2014Co-Authors: Silvia Arroyo-camejo, Andrii Lazariev, Stefan W Hell, Gopalakrishnan BalasubramanianAbstract:Quantum Gates based on geometric phase shifts offer a promising approach for the realization of fault-tolerant quantum computing. Using nitrogen-vacancy centre Qubits in diamond, this study experimentally realises a high-fidelty, non-adiabatic, non-Abelian holonomic single-Qubit Gate at room temperature. At its most fundamental level, circuit-based quantum computation relies on the application of controlled phase shift operations on quantum registers. While these operations are generally compromised by noise and imperfections, quantum Gates based on geometric phase shifts can provide intrinsically fault-tolerant quantum computing. Here we demonstrate the high-fidelity realization of a recently proposed fast (non-adiabatic) and universal (non-Abelian) holonomic single-Qubit Gate, using an individual solid-state spin Qubit under ambient conditions. This fault-tolerant quantum Gate provides an elegant means for achieving the fidelity threshold indispensable for implementing quantum error correction protocols. Since we employ a spin Qubit associated with a nitrogen-vacancy colour centre in diamond, this system is based on integrable and scalable hardware exhibiting strong analogy to current silicon technology. This quantum Gate realization is a promising step towards viable, fault-tolerant quantum computing under ambient conditions.
B L T Plourde - One of the best experts on this subject based on the ideXlab platform.
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suppression of unwanted zz interactions in a hybrid two Qubit system
Physical Review Letters, 2020Co-Authors: Markus Brink, David Mckay, Jared B Hertzberg, Mohammad Ansari, B L T PlourdeAbstract:Mitigating crosstalk errors, whether classical or quantum mechanical, is critically important for achieving high-fidelity entangling Gates in multiQubit circuits. For weakly anharmonic superconducting Qubits, unwanted $ZZ$ interactions can be suppressed by combining Qubits with opposite anharmonicity. We present experimental measurements and theoretical modeling of two-Qubit Gate error for Gates based on the cross resonance interaction between a capacitively shunted flux Qubit and a transmon, and demonstrate the elimination of the $ZZ$ interaction.
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process verification of two Qubit quantum Gates by randomized benchmarking
Physical Review A, 2013Co-Authors: Antonio Corcoles, Jay M Gambetta, Jerry M Chow, John A Smolin, Matthew Ware, J D Strand, B L T Plourde, Matthias SteffenAbstract:We implement a complete randomized benchmarking protocol on a system of two superconducting Qubits. The protocol consists of randomizing over Gates in the Clifford group, which experimentally are generated via an improved two-Qubit cross-resonance Gate implementation and single-Qubit unitaries. From this we extract an optimal average error per Clifford operation of $0.0936$. We also perform an interleaved experiment, alternating our optimal two-Qubit Gate with random two-Qubit Clifford Gates, to obtain a two-Qubit Gate error of $0.0653$. We compare these values with a two-Qubit Gate error of $\ensuremath{\sim}0.12$ obtained from quantum process tomography, which is likely limited by state preparation and measurement errors.
Giuseppe Falci - One of the best experts on this subject based on the ideXlab platform.
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Quantum Sensing 1/f Noise via Pulsed Control of a Two-Qubit Gate
Proceedings, 2019Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Dynamical decoupling sequences are a convenient tool to reduce decoherence due to intrinsic fluctuations with 1 / f power spectrum hindering quantum circuits. We study the possibility to achieve an efficient universal two-Qubit Gate in the presence of 1 / f noise by periodic and Carr-Purcell dynamical decoupling. The high degree of selectivity achieved by these protocols also provides a valuable tool to infer noise characteristics, as the high-frequency cut off and the noise variance. Different scalings of the Gate error with noise variance signal the contribution of different noise statistical properties to the Gate error.
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Quantum Zeno and anti-Zeno effect on a two-Qubit Gate by dynamical decoupling
European Physical Journal-special Topics, 2019Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Controlling the dynamics of entanglement and preventing its disappearance are central requisites for any implementation of quantum information processing. Many solid state Qubits are affected by non-Markovian noise, often with 1/f spectrum. Leading order dephasing effects are captured by treating noise in the quasistatic approximation. In this article we investiGate dynamical decoupling of a two-Qubit Gate studying the crossover from Zeno to anti-Zeno entanglement dynamics obtained by varying the sequence parameters.
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Dynamical decoupling of random telegraph noise in a two-Qubit Gate
International Journal of Quantum Information, 2014Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Controlling the dynamics of entanglement and preventing its disappearance are central requisites for any implementation of quantum information processing. Solid state Qubits are frequently affected by random telegraph noise due to bistable impurities of different nature coupled to the device. In this paper, we investiGate the possibility to achieve an efficient universal two-Qubit Gate in the presence of random telegraph noise by periodic dynamical decoupling. We find an analytic form of the Gate error as a function of the number of applied pulses valid when the Gate time is much shorter then the telegraphic process correlation time. The analysis is further supplemented by exact numerical results demonstrating the feasibility of a highly-efficient universal two-Qubit Gate.
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Optimal tuning of solid-state quantum Gates: A universal two-Qubit Gate
Physical Review B, 2010Co-Authors: Elisabetta Paladino, Antonio D'arrigo, A. Mastellone, Giuseppe FalciAbstract:We present a general route to reduce inhomogeneous broadening in nanodevices due to $1/f$ noise. We apply this method to a universal two-Qubit Gate and demonstrate that for selected optimal couplings, a high-efficient Gate can be implemented even in the presence of $1/f$ noise. Entanglement degradation due to interplay of $1/f$ and quantum noise is quantified via the concurrence. A charge-phase $\sqrt{\text{i}\ensuremath{-}\text{SWAP}}$ Gate for spectra extrapolated from single-Qubit experiments is analyzed.
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Relaxation processes in solid-state two-Qubit Gates
Physica E: Low-dimensional Systems and Nanostructures, 2010Co-Authors: Elisabetta Paladino, Antonio D'arrigo, A. Mastellone, Giuseppe FalciAbstract:Abstract We consider a solid-state two-Qubit Gate subject to relaxation processes originated by transverse and longitudinal fluctuations of the single-Qubit Hamiltonians. We model each noise component as a bosonic bath characterized by a specific power spectrum. We specialize our analysis to a i - SWAP Gate implemented by Josephson Qubits in a fixed coupling scheme. For high-frequency noise spectra extrapolated from single-Qubit experiments we estimate the efficiency of the i - SWAP Gate from the decay of anti-correlations between single-Qubit switching probabilities.
Elisabetta Paladino - One of the best experts on this subject based on the ideXlab platform.
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Quantum Sensing 1/f Noise via Pulsed Control of a Two-Qubit Gate
Proceedings, 2019Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Dynamical decoupling sequences are a convenient tool to reduce decoherence due to intrinsic fluctuations with 1 / f power spectrum hindering quantum circuits. We study the possibility to achieve an efficient universal two-Qubit Gate in the presence of 1 / f noise by periodic and Carr-Purcell dynamical decoupling. The high degree of selectivity achieved by these protocols also provides a valuable tool to infer noise characteristics, as the high-frequency cut off and the noise variance. Different scalings of the Gate error with noise variance signal the contribution of different noise statistical properties to the Gate error.
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Quantum Zeno and anti-Zeno effect on a two-Qubit Gate by dynamical decoupling
European Physical Journal-special Topics, 2019Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Controlling the dynamics of entanglement and preventing its disappearance are central requisites for any implementation of quantum information processing. Many solid state Qubits are affected by non-Markovian noise, often with 1/f spectrum. Leading order dephasing effects are captured by treating noise in the quasistatic approximation. In this article we investiGate dynamical decoupling of a two-Qubit Gate studying the crossover from Zeno to anti-Zeno entanglement dynamics obtained by varying the sequence parameters.
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Dynamical decoupling of random telegraph noise in a two-Qubit Gate
International Journal of Quantum Information, 2014Co-Authors: Antonio D'arrigo, Giuseppe Falci, Elisabetta PaladinoAbstract:Controlling the dynamics of entanglement and preventing its disappearance are central requisites for any implementation of quantum information processing. Solid state Qubits are frequently affected by random telegraph noise due to bistable impurities of different nature coupled to the device. In this paper, we investiGate the possibility to achieve an efficient universal two-Qubit Gate in the presence of random telegraph noise by periodic dynamical decoupling. We find an analytic form of the Gate error as a function of the number of applied pulses valid when the Gate time is much shorter then the telegraphic process correlation time. The analysis is further supplemented by exact numerical results demonstrating the feasibility of a highly-efficient universal two-Qubit Gate.
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Optimal tuning of solid-state quantum Gates: A universal two-Qubit Gate
Physical Review B, 2010Co-Authors: Elisabetta Paladino, Antonio D'arrigo, A. Mastellone, Giuseppe FalciAbstract:We present a general route to reduce inhomogeneous broadening in nanodevices due to $1/f$ noise. We apply this method to a universal two-Qubit Gate and demonstrate that for selected optimal couplings, a high-efficient Gate can be implemented even in the presence of $1/f$ noise. Entanglement degradation due to interplay of $1/f$ and quantum noise is quantified via the concurrence. A charge-phase $\sqrt{\text{i}\ensuremath{-}\text{SWAP}}$ Gate for spectra extrapolated from single-Qubit experiments is analyzed.
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Relaxation processes in solid-state two-Qubit Gates
Physica E: Low-dimensional Systems and Nanostructures, 2010Co-Authors: Elisabetta Paladino, Antonio D'arrigo, A. Mastellone, Giuseppe FalciAbstract:Abstract We consider a solid-state two-Qubit Gate subject to relaxation processes originated by transverse and longitudinal fluctuations of the single-Qubit Hamiltonians. We model each noise component as a bosonic bath characterized by a specific power spectrum. We specialize our analysis to a i - SWAP Gate implemented by Josephson Qubits in a fixed coupling scheme. For high-frequency noise spectra extrapolated from single-Qubit experiments we estimate the efficiency of the i - SWAP Gate from the decay of anti-correlations between single-Qubit switching probabilities.
L.m.k. Vandersypen - One of the best experts on this subject based on the ideXlab platform.
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single shot correlations and two Qubit Gate of solid state spins
Bulletin of the American Physical Society, 2012Co-Authors: L.m.k. VandersypenAbstract:Measurement of coupled quantum systems plays a central role in quantum information processing. We have realized independent single-shot read-out of two electron spins in a double quantum dot. The read-out method is allelectrical, cross-talk between the two measurements is negligible and read-out fidelities are about 86% on average. This allows us to directly probe the anticorrelations between two spins prepared in a singlet state, and to demonstrate the operation of the two-Qubit exchange Gate on a complete set of basis states. The results provide a possible route to the realization and efficient
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single shot correlations and two Qubit Gate of solid state spins
Science, 2011Co-Authors: Katja C Nowack, M Shafiei, Martin Laforest, Guenevere E D K Prawiroatmodjo, L R Schreiber, C Reichl, Werner Wegscheider, L.m.k. VandersypenAbstract:Measurement of coupled quantum systems plays a central role in quantum information processing. We have realized independent single-shot read-out of two electron spins in a double quantum dot. The read-out method is all-electrical, cross-talk between the two measurements is negligible, and read-out fidelities are ~86% on average. This allows us to directly probe the anticorrelations between two spins prepared in a singlet state and to demonstrate the operation of the two-Qubit exchange Gate on a complete set of basis states. The results provide a possible route to the realization and efficient characterization of multiQubit quantum circuits based on single quantum dot spins.
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Bulk spin quantum computation: toward large-scale quantum computation
1998 IEEE International Solid-State Circuits Conference. Digest of Technical Papers ISSCC. First Edition (Cat. No.98CH36156), 1998Co-Authors: I.l. Chuang, L.m.k. Vandersypen, J.s. HarrisAbstract:Quantum computation offers the potential for solving specific problems exponentially faster than the best classical machines, by virtue of its non-classical dynamics and information representation. Quantum mechanical bits (called 'Qubits') can be both 0 and 1 at the same time, in which case the Qubit is said to be in a superposition state. A quantum Gate with input 0 or 1 gives the same output as a classical Gate, but if the input is 0 and 1 simultaneously, the quantum Gate performs the two corresponding operations simultaneously. Similarly, a 2-Qubit Gate with an input state prepared as a superposition of the 4 combinations 00, 01, 10 and 11, performs four simultaneous computations. In general, an N-Qubit Gate could perform 2/sup N/ computations at the same time. So as we increase the size of the system, the computational capacity of the apparatus goes up exponentially, compared to linearly for a classical computer. Using commercial NMR-spectrometers, simple quantum circuits are experimentally implemented consisting of multiple cascaded logic Gates.
