The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Hong-fu Wang - One of the best experts on this subject based on the ideXlab platform.
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scheme for implementing multitarget Qubit Controlled not gate of photons and Controlled phase gate of electron spins via quantum dot microcavity coupled system
Quantum Information Processing, 2016Co-Authors: Chenghua Bai, Dongyang Wang, Wenxue Cui, Xinxin Jiang, Hong-fu WangAbstract:We propose a deterministic scheme to implement the multiQubit Controlled-NOT gate of photons and multiQubit Controlled-phase gate of electron spins with one Control Qubit and multiple target Qubits using quantum dots in double-sided optical cavities. The scheme is based on spin selective photon reflection from the cavity and can be achieved in a nondestructive way. We assess the feasibility of the scheme and show that the gates can be implemented with high average fidelities by choosing the realistic system parameters appropriately. The scheme is useful in quantum information processing such as entanglement preparation, quantum error correction, and quantum algorithms.
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a scheme for direct implementation of a two target Qubit Controlled phase gate with quantum dots in coupled photonic crystal cavities without using classical laser pulses
Laser Physics Letters, 2014Co-Authors: Xinxin Jiang, Wenxue Cui, Hong-fu WangAbstract:We propose a scheme to implement a three-Qubit Controlled phase gate with one Control Qubit and two target Qubits using quantum dots (QDs) in two coupled photonic crystal (PC) cavities A and B. In the scheme, three QDs are embedded in two coupled photonic crystal cavities and the transitions between the levels are only coupled to the cavity modes without being driven by the classical laser fields. We investigate the dynamics of the system consisting of resonant and off-resonant couplings between the cavity modes and QDs and solve the time-dependent Schrodinger equation analytically. The results show that a three-Qubit Controlled phase gate can be directly implemented using one operational step, by exchanging a single photon between the PC cavities A and B. This scheme greatly simplifies the gate operation in experiments.
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one step implementation of a multiQubit phase gate with one Control Qubit and multiple target Qubits in coupled cavities
Optics Letters, 2014Co-Authors: Hong-fu Wang, Aidong Zhu, Shou ZhangAbstract:We propose a one-step scheme to implement a multiQubit Controlled phase gate with one Qubit simultaneously Controlling multiple Qubits with three-level atoms at distant nodes in coupled cavity arrays. Selective Qubit–Qubit couplings are achieved by adiabatically eliminating the atomic excited states and photonic states, and the required phase shifts between the Control Qubit and any target Qubit can be realized through suitable choices of the parameters of the external fields. Moreover, the effective model is robust against decoherence because neither the atoms nor the field modes are excited during the gate operation, leading to a useful step toward scalable quantum computing networks.
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one step implementation of multiQubit phase gate with one Control Qubit and multiple target Qubits in coupled cavities
arXiv: Quantum Physics, 2014Co-Authors: Hong-fu Wang, Aidong Zhu, Shou ZhangAbstract:We propose a one-step scheme to implement a multiQubit Controlled phase gate of one Qubit simultaneously Controlling multiple Qubits with three-level atoms at distant nodes in coupled cavity arrays. The selective Qubit-Qubit couplings are achieved by adiabatically eliminating the atomic excited states and photonic states and the required phase shifts between the Control Qubit and any target Qubit can be realized through suitable choices of the parameters of the external fields. Moreover, the effective model is robust against decoherence because neither the atoms nor the field modes during the gate operation are excited, leading to a useful step toward scalable quantum computing networks.
Chui-ping Yang - One of the best experts on this subject based on the ideXlab platform.
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Multi-target-Qubit unconventional geometric phase gate in a multi-cavity system
Scientific Reports, 2016Co-Authors: Qi-ping Su, Shao-jie Xiong, Chui-ping YangAbstract:: Cavity-based large scale quantum information processing (QIP) may involve multiple cavities and require performing various quantum logic operations on Qubits distributed in different cavities. Geometric-phase-based quantum computing has drawn much attention recently, which offers advantages against inaccuracies and local fluctuations. In addition, multiQubit gates are particularly appealing and play important roles in QIP. We here present a simple and efficient scheme for realizing a multi-target-Qubit unconventional geometric phase gate in a multi-cavity system. This multiQubit phase gate has a common Control Qubit but different target Qubits distributed in different cavities, which can be achieved using a single-step operation. The gate operation time is independent of the number of Qubits and only two levels for each Qubit are needed. This multiQubit gate is generic, e.g., by performing single-Qubit operations, it can be converted into two types of significant multi-target-Qubit phase gates useful in QIP. The proposal is quite general, which can be used to accomplish the same task for a general type of Qubits such as atoms, NV centers, quantum dots, and superconducting Qubits.
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MultiQubit tunable phase gate of one Qubit simultaneously Controlling n Qubits in a cavity
Physical Review A, 2010Co-Authors: Chui-ping Yang, Shi-biao Zheng, Franco NoriAbstract:We propose how to realize a multiQubit tunable phase gate of one Qubit simultaneously Controlling $n$ Qubits with four-level quantum systems in a cavity or coupled to a resonator. Each of the $n$ two-Qubit Controlled-phase (CP) gates involved in this multiQubit phase gate has a shared Control Qubit but a {\it different} target Qubit. In this propose, the two lowest levels of each system represent the two logical states of a Qubit while the two higher-energy intermediate levels are used for the gate implementation. The method presented here operates essentially by creating a single photon through the Control Qubit, which then induces a phase shift to the state of each target Qubit. The phase shifts on each target Qubit can be adjusted by changing the Rabi frequencies of the pulses applied to the target Qubit systems. The operation time for the gate implementation is independent of the number of Qubits, and neither adjustment of the Qubit level spacings nor adjustment of the cavity mode frequency during the gate operation is required by this proposal. It is also noted that this approach can be applied to implement certain types of significant multiQubit phase gates, e.g., the multiQubit phase gate consisting of $n$ two-Qubit CP gates which are key elements in quantum Fourier transforms. A possible physical implementation of our approach is presented. Our proposal is quite general, and can be applied to physical systems such as various types of superconducting devices coupled to a resonator and trapped atoms in a cavity.
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multiQubit tunable phase gate of one Qubit simultaneously Controlling n Qubits in a cavity
Physical Review A, 2010Co-Authors: Chui-ping Yang, Shi-biao Zheng, Franco NoriAbstract:We propose how to realize a multiQubit tunable phase gate of one Qubit simultaneously Controlling $n$ Qubits with four-level quantum systems in a cavity or coupled to a resonator. Each of the $n$ two-Qubit Controlled-phase (cp) gates involved in this multiQubit phase gate has a shared Control Qubit but a different target Qubit. In this proposal, the two lowest levels of each system represent the two logical states of a Qubit while the two higher-energy intermediate levels are used for the gate implementation. The method presented here operates essentially by creating a single photon through the Control Qubit, which then induces a phase shift to the state of each target Qubit. The phase shifts on each target Qubit can be adjusted by changing the Rabi frequencies of the pulses applied to the target Qubit systems. The operation time for the gate implementation is independent of the number of Qubits, and neither adjustment of the Qubit level spacings nor adjustment of the cavity mode frequency during the gate operation is required by this proposal. It is also noted that this approach can be applied to implement certain types of significant multiQubit phase gates (e.g., the multiQubit phase gate consisting of $n$ two-Qubit cp gates which are key elements in quantum Fourier transforms). A possible physical implementation of our approach is presented. Our proposal is quite general and can be applied to physical systems such as various types of superconducting devices coupled to a resonator and trapped atoms in a cavity.
Franco N C Wong - One of the best experts on this subject based on the ideXlab platform.
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deterministic Controlled not gate for single photon two Qubit quantum logic
Physical Review Letters, 2004Co-Authors: Marco Fiorentino, Franco N C WongAbstract:We demonstrate a robust implementation of a deterministic linear-optical Controlled-not gate for single-photon two-Qubit quantum logic. A polarization Sagnac interferometer with an embedded 45 degrees -oriented dove prism is used to enable the polarization Control Qubit to act on the momentum (spatial) target Qubit of the same photon. The optical Controlled-not gate requires no active stabilization because the two spatial modes share a common path, and it is used to entangle the polarization and momentum Qubits.
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deterministic Controlled not gate for single photon two Qubit quantum logic
Physical Review Letters, 2004Co-Authors: Marco Fiorentino, Franco N C WongAbstract:We demonstrate a robust implementation of a deterministic linear-optical Controlled-not gate for single-photon two-Qubit quantum logic. A polarization Sagnac interferometer with an embedded 45 \ifmmode^\circ\else\textdegree\fi{}-oriented dove prism is used to enable the polarization Control Qubit to act on the momentum (spatial) target Qubit of the same photon. The optical Controlled-not gate requires no active stabilization because the two spatial modes share a common path, and it is used to entangle the polarization and momentum Qubits.
Franco Nori - One of the best experts on this subject based on the ideXlab platform.
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MultiQubit tunable phase gate of one Qubit simultaneously Controlling n Qubits in a cavity
Physical Review A, 2010Co-Authors: Chui-ping Yang, Shi-biao Zheng, Franco NoriAbstract:We propose how to realize a multiQubit tunable phase gate of one Qubit simultaneously Controlling $n$ Qubits with four-level quantum systems in a cavity or coupled to a resonator. Each of the $n$ two-Qubit Controlled-phase (CP) gates involved in this multiQubit phase gate has a shared Control Qubit but a {\it different} target Qubit. In this propose, the two lowest levels of each system represent the two logical states of a Qubit while the two higher-energy intermediate levels are used for the gate implementation. The method presented here operates essentially by creating a single photon through the Control Qubit, which then induces a phase shift to the state of each target Qubit. The phase shifts on each target Qubit can be adjusted by changing the Rabi frequencies of the pulses applied to the target Qubit systems. The operation time for the gate implementation is independent of the number of Qubits, and neither adjustment of the Qubit level spacings nor adjustment of the cavity mode frequency during the gate operation is required by this proposal. It is also noted that this approach can be applied to implement certain types of significant multiQubit phase gates, e.g., the multiQubit phase gate consisting of $n$ two-Qubit CP gates which are key elements in quantum Fourier transforms. A possible physical implementation of our approach is presented. Our proposal is quite general, and can be applied to physical systems such as various types of superconducting devices coupled to a resonator and trapped atoms in a cavity.
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multiQubit tunable phase gate of one Qubit simultaneously Controlling n Qubits in a cavity
Physical Review A, 2010Co-Authors: Chui-ping Yang, Shi-biao Zheng, Franco NoriAbstract:We propose how to realize a multiQubit tunable phase gate of one Qubit simultaneously Controlling $n$ Qubits with four-level quantum systems in a cavity or coupled to a resonator. Each of the $n$ two-Qubit Controlled-phase (cp) gates involved in this multiQubit phase gate has a shared Control Qubit but a different target Qubit. In this proposal, the two lowest levels of each system represent the two logical states of a Qubit while the two higher-energy intermediate levels are used for the gate implementation. The method presented here operates essentially by creating a single photon through the Control Qubit, which then induces a phase shift to the state of each target Qubit. The phase shifts on each target Qubit can be adjusted by changing the Rabi frequencies of the pulses applied to the target Qubit systems. The operation time for the gate implementation is independent of the number of Qubits, and neither adjustment of the Qubit level spacings nor adjustment of the cavity mode frequency during the gate operation is required by this proposal. It is also noted that this approach can be applied to implement certain types of significant multiQubit phase gates (e.g., the multiQubit phase gate consisting of $n$ two-Qubit cp gates which are key elements in quantum Fourier transforms). A possible physical implementation of our approach is presented. Our proposal is quite general and can be applied to physical systems such as various types of superconducting devices coupled to a resonator and trapped atoms in a cavity.
Weining Zhang - One of the best experts on this subject based on the ideXlab platform.
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one step implementation of a hybrid fredkin gate with quantum memories and single superconducting Qubit in circuit qed and its applications
arXiv: Quantum Physics, 2018Co-Authors: Tong Liu, Baoqing Guo, Weining ZhangAbstract:In a recent remarkable experiment [R. B. Patel et al., Science advances 2, e1501531 (2016)], a 3-Qubit quantum Fredkin (i.e., Controlled-SWAP) gate was demonstrated by using linear optics. Here we propose a simple experimental scheme by utilizing the dispersive interaction in superconducting quantum circuit to implement a hybrid Fredkin gate with a superconducting flux Qubit as the Control Qubit and two separated quantum memories as the target qudits. The quantum memories considered here are prepared by the superconducting coplanar waveguide resonators or nitrogen-vacancy center ensembles. In particular, it is shown that this Fredkin gate can be realized using a single-step operation and more importantly, each target qudit can be in an arbitrary state with arbitrary degrees of freedom. Furthermore, we show that this experimental scheme has many potential applications in quantum computation and quantum information processing such as generating arbitrary entangled states (discrete-variable states or continuous-variable states) of the two memories, measuring the fidelity and the entanglement between the two memories. With state-of-the-art circuit QED technology, the numerical simulation is performed to demonstrate that two-memory NOON states, entangled coherent states, and entangled cat states can be efficiently synthesized.
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one step implementation of a hybrid fredkin gate with quantum memories and single superconducting Qubit in circuit qed and its applications
Optics Express, 2018Co-Authors: Tong Liu, Baoqing Guo, Weining ZhangAbstract:In a recent remarkable experiment [Sci. Adv. 2, e1501531 (2016)], a 3-Qubit quantum Fredkin (i.e., Controlled-SWAP) gate was demonstrated by using linear optics. Here we propose a simple experimental scheme by utilizing the dispersive interaction in superconducting quantum circuit to implement a hybrid Fredkin gate with a superconducting flux Qubit as the Control Qubit and two separated quantum memories as the target qudits. The quantum memories considered here are prepared by the superconducting coplanar waveguide resonators or nitrogen-vacancy center ensembles. In particular, it is shown that this Fredkin gate can be realized using a single-step operation and more importantly, each target qudit can be in an arbitrary state with arbitrary degrees of freedom. Furthermore, we show that this experimental scheme has many potential applications in quantum computation and quantum information processing such as generating arbitrary entangled states (discrete-variable states or continuous-variable states) of the two memories, measuring the fidelity and the entanglement between the two memories. With state-of-the-art circuit QED technology, the numerical simulation is performed to demonstrate that two-memory NOON states, entangled coherent states, and entangled cat states can be efficiently synthesized.