This paper proposes a scheme for realization of a three-qubit Toffoli gate operation using three four-level atoms by a selective atom-field interaction in a cavity quantum electrodynamics system. In the proposed proto...This paper proposes a scheme for realization of a three-qubit Toffoli gate operation using three four-level atoms by a selective atom-field interaction in a cavity quantum electrodynamics system. In the proposed protocol, the quantum information is encoded on the stable ground states of atoms, and atomic spontaneous emission is negligible as the large atom-avity detuning effectively suppresses the spontaneous decay of the atoms. The influence of the dissipation on fidelity and success probability of the three-qubit Toffoli gate is also discussed. The scheme can also be applied to realize an N-qubit Toffoli gate and the interaction time required does not rise with increasing the number of qubits.展开更多
We propose a potentially practical scheme to implement an approximate three-qubit Toffoli gate by a single resonant interaction in dissipative cavity QED in which the cavity mode decay and atomic spontaneous emission ...We propose a potentially practical scheme to implement an approximate three-qubit Toffoli gate by a single resonant interaction in dissipative cavity QED in which the cavity mode decay and atomic spontaneous emission are considered. The scheme does not require two-qubit controlled-NOT gates but uses a three-qubit phase gate and two Hadamard gates, where the approximate phase gate can be implemented by only a single dissipative resonant interaction of atoms with the cavity mode. Discussions are made for the advantages and the experimental feasibility of our scheme.展开更多
This paper proposes two schemes for implementing three-qubit Toffoli gate with an atom （as target qubit） sent through a two-mode cavity （as control qubits）. The first scheme is based on the large-detuning atom cav...This paper proposes two schemes for implementing three-qubit Toffoli gate with an atom （as target qubit） sent through a two-mode cavity （as control qubits）. The first scheme is based on the large-detuning atom cavity field interaction and the second scheme is based on the resonant atom-field interaction. Both the situations with and without cavity decay and atomic spontaneous emission are considered. The advantages and the experimental feasibility of these two schemes are discussed.展开更多
We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport ve...We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport velocity,the n-qubit Toffoli gate can be realized with high fidelity and high successful probability under current experimentalconditions,which depends on a single resonant interaction with n trapped ions and has constant implementation timewith the increase of qubits.We show that the increase of the ion number can improve the fidelity and the successfulprobability of the Toffoli gate.展开更多
In this paper, we demonstrate n-party controlled unitary gate implementations locally on arbitrary remote state through linear entangled channel where control parties share entanglement with the adjacent control parti...In this paper, we demonstrate n-party controlled unitary gate implementations locally on arbitrary remote state through linear entangled channel where control parties share entanglement with the adjacent control parties and only one of them shares entanglement with the target party. In such a network, we describe the protocol of simultaneous implementation of controlled-Hermitian gate starting from three party scenarios. We also explicate the implementation of three party controlled-Unitary gates, a generalized form of Toffoli gate and subsequently generalize the protocol for n-party using minimal cost.展开更多
With the recent demonstration of quantum computers,interests in the field of reversible logic synthesis and optimization have taken a different turn.As every quantum operation is inherently reversible,there is an imme...With the recent demonstration of quantum computers,interests in the field of reversible logic synthesis and optimization have taken a different turn.As every quantum operation is inherently reversible,there is an immense motivation for exploring reversible circuit design and optimization.When it comes to faults in circuits,the parity-preserving feature donates to the detection of permanent and temporary faults.In the context of reversible circuits,the parity-preserving property ensures that the input and output parities are equal.In this paper we suggest six parity-preserving reversible blocks(ZFATSL)with improved quantum cost.The reversible blocks are synthesized using an existing synthesis method that generates a netlist of multiple-control Toffoli(MCT)gates.Various optimization rules are applied at the reversible circuit level,followed by transformation into a netlist of elementary quantum gates from the NCV library.The designs of full-adder and unsigned and signed multipliers are proposed using the functional blocks that possess parity-preserving properties.The proposed designs are compared with state-of-the-art methods and found to be better in terms of cost of realization.Average savings of 25.04%,20.89%,21.17%,and 51.03%,and 18.59%,13.82%,13.82%,and 27.65% respectively,are observed for 4-bit unsigned and 5-bit signed multipliers in terms of quantum cost,garbage output,constant input,and gate count as compared to recent works.展开更多
基金Project supported by the Natural Science Foundation of Hunan Province,China (Grant No 06JJ50118)
文摘This paper proposes a scheme for realization of a three-qubit Toffoli gate operation using three four-level atoms by a selective atom-field interaction in a cavity quantum electrodynamics system. In the proposed protocol, the quantum information is encoded on the stable ground states of atoms, and atomic spontaneous emission is negligible as the large atom-avity detuning effectively suppresses the spontaneous decay of the atoms. The influence of the dissipation on fidelity and success probability of the three-qubit Toffoli gate is also discussed. The scheme can also be applied to realize an N-qubit Toffoli gate and the interaction time required does not rise with increasing the number of qubits.
基金The project supported by National Natural Science Foundation of China under Grant No.10774042National Fundamental Basic Research Program of China under Grant No.2005CB724502+2 种基金Natural Science Foundation of Hunan Province under Grant No.05JJ30005the Scientific Research Fund of Educational Department of Hunan Province under Grant No.05C756the Scientific Research Fund of Hunan Institute of Humanity and Science and Technology under Grant No.2005A008
文摘We propose a potentially practical scheme to implement an approximate three-qubit Toffoli gate by a single resonant interaction in dissipative cavity QED in which the cavity mode decay and atomic spontaneous emission are considered. The scheme does not require two-qubit controlled-NOT gates but uses a three-qubit phase gate and two Hadamard gates, where the approximate phase gate can be implemented by only a single dissipative resonant interaction of atoms with the cavity mode. Discussions are made for the advantages and the experimental feasibility of our scheme.
基金supported by the National Natural Science Foundation of China (Grant No 60667001)
文摘This paper proposes two schemes for implementing three-qubit Toffoli gate with an atom （as target qubit） sent through a two-mode cavity （as control qubits）. The first scheme is based on the large-detuning atom cavity field interaction and the second scheme is based on the resonant atom-field interaction. Both the situations with and without cavity decay and atomic spontaneous emission are considered. The advantages and the experimental feasibility of these two schemes are discussed.
基金supported by National Natural Science Foundation of China under Grant Nos.10774163 and 10774042partly by the National Fundamental Research Program of China under Grant Nos.2005CB724502 and 2006CB921203
文摘We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport velocity,the n-qubit Toffoli gate can be realized with high fidelity and high successful probability under current experimentalconditions,which depends on a single resonant interaction with n trapped ions and has constant implementation timewith the increase of qubits.We show that the increase of the ion number can improve the fidelity and the successfulprobability of the Toffoli gate.
文摘In this paper, we demonstrate n-party controlled unitary gate implementations locally on arbitrary remote state through linear entangled channel where control parties share entanglement with the adjacent control parties and only one of them shares entanglement with the target party. In such a network, we describe the protocol of simultaneous implementation of controlled-Hermitian gate starting from three party scenarios. We also explicate the implementation of three party controlled-Unitary gates, a generalized form of Toffoli gate and subsequently generalize the protocol for n-party using minimal cost.
文摘With the recent demonstration of quantum computers,interests in the field of reversible logic synthesis and optimization have taken a different turn.As every quantum operation is inherently reversible,there is an immense motivation for exploring reversible circuit design and optimization.When it comes to faults in circuits,the parity-preserving feature donates to the detection of permanent and temporary faults.In the context of reversible circuits,the parity-preserving property ensures that the input and output parities are equal.In this paper we suggest six parity-preserving reversible blocks(ZFATSL)with improved quantum cost.The reversible blocks are synthesized using an existing synthesis method that generates a netlist of multiple-control Toffoli(MCT)gates.Various optimization rules are applied at the reversible circuit level,followed by transformation into a netlist of elementary quantum gates from the NCV library.The designs of full-adder and unsigned and signed multipliers are proposed using the functional blocks that possess parity-preserving properties.The proposed designs are compared with state-of-the-art methods and found to be better in terms of cost of realization.Average savings of 25.04%,20.89%,21.17%,and 51.03%,and 18.59%,13.82%,13.82%,and 27.65% respectively,are observed for 4-bit unsigned and 5-bit signed multipliers in terms of quantum cost,garbage output,constant input,and gate count as compared to recent works.
