The Experts below are selected from a list of 1539 Experts worldwide ranked by ideXlab platform
Shou Zhang - One of the best experts on this subject based on the ideXlab platform.
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teleportation of a Toffoli Gate among distant solid state qubits with quantum dots embedded in optical microcavities
Scientific Reports, 2015Co-Authors: Wenxue Cui, Shou Zhang, Aidong Zhu, Hongfu Wang, Dongyang Wang, Chenghua Bai, Qi GuoAbstract:Teleportation of unitary operations can be viewed as a quantum remote control. The remote realization of robust multiqubit logic Gates among distant long-lived qubit registers is a key challenge for quantum computation and quantum information processing. Here we propose a simple and deterministic scheme for teleportation of a Toffoli Gate among three spatially separated electron spin qubits in optical microcavities by using local linear optical operations, an auxiliary electron spin, two circularly-polarized entangled photon pairs, photon measurements, and classical communication. We assess the feasibility of the scheme and show that the scheme can be achieved with high average fidelity under the current technology. The scheme opens promising perspectives for constructing long-distance quantum communication and quantum computation networks with solid-state qubits.
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robust Toffoli Gate originating from stark shifts
Journal of The Optical Society of America B-optical Physics, 2012Co-Authors: Xiaoqiang Shao, Taiyu Zheng, Shou ZhangAbstract:A method for synthesizing the Toffoli Gate is proposed based solely on the Stark shifts of three superconducting quantum interference devices (SQUIDs). This scheme is robust against the effect of decoherence, since it operates with no excitation of SQUIDs and the coplanar waveguide cavity. The obtained fidelity of the Toffoli Gate is high, corresponding to the current typical experimental parameters, and an equivalent physical model for conveniently addressing qubits is also constructed in the coupled-cavity array system.
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one step implementation of the Toffoli Gate via quantum zeno dynamics
Physics Letters A, 2009Co-Authors: Xiaoqiang Shao, Shou Zhang, Hongfu Wang, Li Chen, Kyuhwang YeonAbstract:Based on the quantum Zeno dynamics, we present a scheme for one-step implementation of a Toffoli Gate via manipulating three rf superconducting quantum interference device (SQUID) qubits to resonantly interact with a superconducting cavity. The effects of decoherence such as spontaneous emission and the loss of cavity are also considered.
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efficient scheme for implementing an n qubit Toffoli Gate by a single resonant interaction with cavity quantum electrodynamics
Physical Review A, 2007Co-Authors: Xiaoqiang Shao, Shou Zhang, Aidong Zhu, Jeansoo Chung, Kyuhwang YeonAbstract:A scheme for implementing a three-qubit Toffoli Gate with atoms sent through a microwave cavity is proposed by choosing nonidentical coupling constants between the atoms and cavity. The scheme can be generalized to implement an $N$-qubit Toffoli Gate and the gating time does not change with an increase of the number of qubits.
Xiaoqiang Shao - One of the best experts on this subject based on the ideXlab platform.
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one step implementation of Toffoli Gate for neutral atoms based on unconventional rydberg pumping
Optics Express, 2020Co-Authors: Hongda Yin, Gangcheng Wang, Xiaoqiang ShaoAbstract:Compared with the idea of universal quantum computation, a direct synthesis of a multiqubit logic Gate can greatly improve the efficiency of quantum information processing tasks. Here we propose an efficient scheme to implement a three-qubit controlled-not (Toffoli) Gate of neutral atoms based on unconventional Rydberg pumping. By adjusting the strengths of Rabi frequencies of driving fields, the Toffoli Gate can be achieved within one step, which is also insensitive to the fluctuation of the Rydberg-Rydberg interaction. Considering different atom alignments, we can obtain a high-fidelity Toffoli Gate at the same operation time ∼7 μs. In addition, our scheme can be further extended to the four-qubit case without altering the operating time.
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robust Toffoli Gate originating from stark shifts
Journal of The Optical Society of America B-optical Physics, 2012Co-Authors: Xiaoqiang Shao, Taiyu Zheng, Shou ZhangAbstract:A method for synthesizing the Toffoli Gate is proposed based solely on the Stark shifts of three superconducting quantum interference devices (SQUIDs). This scheme is robust against the effect of decoherence, since it operates with no excitation of SQUIDs and the coplanar waveguide cavity. The obtained fidelity of the Toffoli Gate is high, corresponding to the current typical experimental parameters, and an equivalent physical model for conveniently addressing qubits is also constructed in the coupled-cavity array system.
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one step implementation of the Toffoli Gate via quantum zeno dynamics
Physics Letters A, 2009Co-Authors: Xiaoqiang Shao, Shou Zhang, Hongfu Wang, Li Chen, Kyuhwang YeonAbstract:Based on the quantum Zeno dynamics, we present a scheme for one-step implementation of a Toffoli Gate via manipulating three rf superconducting quantum interference device (SQUID) qubits to resonantly interact with a superconducting cavity. The effects of decoherence such as spontaneous emission and the loss of cavity are also considered.
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efficient scheme for implementing an n qubit Toffoli Gate by a single resonant interaction with cavity quantum electrodynamics
Physical Review A, 2007Co-Authors: Xiaoqiang Shao, Shou Zhang, Aidong Zhu, Jeansoo Chung, Kyuhwang YeonAbstract:A scheme for implementing a three-qubit Toffoli Gate with atoms sent through a microwave cavity is proposed by choosing nonidentical coupling constants between the atoms and cavity. The scheme can be generalized to implement an $N$-qubit Toffoli Gate and the gating time does not change with an increase of the number of qubits.
Jaromir Fiurasek - One of the best experts on this subject based on the ideXlab platform.
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tomographic characterization of a linear optical quantum Toffoli Gate
Physical Review A, 2015Co-Authors: Michal Micuda, Martina Mikova, Ivo Straka, Michal Sedlak, Miloslav Dusek, Miroslav Ježek, Jaromir FiurasekAbstract:We report on a detailed characterization of a three-qubit linear optical quantum Toffoli Gate. Our experiment utilizes correlated photon pairs generated in the process of spontaneous parametric down-conversion. Two qubits are encoded into polarization and spatial degrees of freedom of a signal photon, and the third qubit is represented by polarization of an idler photon. The linear optical Toffoli Gate is implemented by interference of photons on a partially polarizing beam splitter inserted inside a Mach Zehnder interferometer formed by two calcite beam displacers. We have measured 4032 different two-photon coincidences, which allows us to estimate the fidelity of the Gate to be 90%. Although these data are not tomographically complete, we show that they are sufficient for a reliable reconstruction of the quantum process matrix of the Gate via the recently proposed maximum likelihood--maximum entropy estimation procedure. To probe the entangling capability of the Gate, we have investiGated generation of three-qubit GHZ states from fully and partially separable input states and we have performed a full tomography of the output states. We compare the reconstructed states with theoretical predictions obtained with the use of the estimated quantum process matrix and obtain a very good agreement.
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efficient experimental estimation of fidelity of linear optical quantum Toffoli Gate
Physical Review Letters, 2013Co-Authors: Michal Micuda, Martina Mikova, Ivo Straka, Michal Sedlak, Miloslav Dusek, Miroslav Ježek, Jaromir FiurasekAbstract:We propose an efficiently measurable lower bound on quantum process fidelity of N-qubit controlled-Z Gates. This bound is determined by average output state fidelities for N partially conjuGate product bases. A distinct advantage of our approach is that only fidelities with product states need to be measured while keeping the total number of measurements much smaller than what is necessary for full quantum process tomography. As an application, we use this method to experimentally estimate quantum process fidelity F of a three-qubit linear optical quantum Toffoli Gate and we find that F≥0.83. We also demonstrate the entangling capability of the Gate by preparing Greenberger-Horne-Zeilinger-type three-qubit entangled states from input product states.
Kyuhwang Yeon - One of the best experts on this subject based on the ideXlab platform.
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one step implementation of the Toffoli Gate via quantum zeno dynamics
Physics Letters A, 2009Co-Authors: Xiaoqiang Shao, Shou Zhang, Hongfu Wang, Li Chen, Kyuhwang YeonAbstract:Based on the quantum Zeno dynamics, we present a scheme for one-step implementation of a Toffoli Gate via manipulating three rf superconducting quantum interference device (SQUID) qubits to resonantly interact with a superconducting cavity. The effects of decoherence such as spontaneous emission and the loss of cavity are also considered.
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efficient scheme for implementing an n qubit Toffoli Gate by a single resonant interaction with cavity quantum electrodynamics
Physical Review A, 2007Co-Authors: Xiaoqiang Shao, Shou Zhang, Aidong Zhu, Jeansoo Chung, Kyuhwang YeonAbstract:A scheme for implementing a three-qubit Toffoli Gate with atoms sent through a microwave cavity is proposed by choosing nonidentical coupling constants between the atoms and cavity. The scheme can be generalized to implement an $N$-qubit Toffoli Gate and the gating time does not change with an increase of the number of qubits.
Michal Micuda - One of the best experts on this subject based on the ideXlab platform.
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tomographic characterization of a linear optical quantum Toffoli Gate
Physical Review A, 2015Co-Authors: Michal Micuda, Martina Mikova, Ivo Straka, Michal Sedlak, Miloslav Dusek, Miroslav Ježek, Jaromir FiurasekAbstract:We report on a detailed characterization of a three-qubit linear optical quantum Toffoli Gate. Our experiment utilizes correlated photon pairs generated in the process of spontaneous parametric down-conversion. Two qubits are encoded into polarization and spatial degrees of freedom of a signal photon, and the third qubit is represented by polarization of an idler photon. The linear optical Toffoli Gate is implemented by interference of photons on a partially polarizing beam splitter inserted inside a Mach Zehnder interferometer formed by two calcite beam displacers. We have measured 4032 different two-photon coincidences, which allows us to estimate the fidelity of the Gate to be 90%. Although these data are not tomographically complete, we show that they are sufficient for a reliable reconstruction of the quantum process matrix of the Gate via the recently proposed maximum likelihood--maximum entropy estimation procedure. To probe the entangling capability of the Gate, we have investiGated generation of three-qubit GHZ states from fully and partially separable input states and we have performed a full tomography of the output states. We compare the reconstructed states with theoretical predictions obtained with the use of the estimated quantum process matrix and obtain a very good agreement.
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efficient experimental estimation of fidelity of linear optical quantum Toffoli Gate
Physical Review Letters, 2013Co-Authors: Michal Micuda, Martina Mikova, Ivo Straka, Michal Sedlak, Miloslav Dusek, Miroslav Ježek, Jaromir FiurasekAbstract:We propose an efficiently measurable lower bound on quantum process fidelity of N-qubit controlled-Z Gates. This bound is determined by average output state fidelities for N partially conjuGate product bases. A distinct advantage of our approach is that only fidelities with product states need to be measured while keeping the total number of measurements much smaller than what is necessary for full quantum process tomography. As an application, we use this method to experimentally estimate quantum process fidelity F of a three-qubit linear optical quantum Toffoli Gate and we find that F≥0.83. We also demonstrate the entangling capability of the Gate by preparing Greenberger-Horne-Zeilinger-type three-qubit entangled states from input product states.
