Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Laser Physics Letters

Universal quantum gates for atomic systems assisted by Faraday rotation

Guo‐Zhu Song, Mei Zhang

Published Jul 17, 2015• 0 citations
Publisher

Abstract

Both cavity quantum electrodynamics and photons are promising candidates for quantum information processing. Here we present two efficient schemes for universal quantum gates, that is, Fredkin gates and SWAP gates on atomic systems, assisted by Faraday rotation catalyzed by an auxiliary single photon. These gates are achieved by successfully reflecting an auxiliary single photon from an optical cavity with a single-trapped atom. They do not require additional qubits and they only need some linear-optical elements besides the nonlinear interaction between the flying photon and the atoms in the optical cavities. Moreover, these two universal quantum gates are robust. A high fidelity can be achieved in our schemes with current experimental technology. They may be very useful in quantum information processing in future, with the great progress on controlling atomic systems.

DOI
10.1088/1612-2011/12/8/085203

Related papers

Universal quantum gates for hybrid systems assisted by quantum dots inside double-sided optical microcavities

Hai‐Rui Wei, Fu‐Guo Deng

We present some deterministic schemes to construct universal quantum gates, that is, controlled- not, three-qubit Toffoli, and Fredkin gates, between flying photon qubits and stationary electron-spin qubits assisted by quantum dots inside double-sided optical microcavities. The control qubit of our gates is encoded on the polarization of the moving single photon and the target qubits are encoded on the confined electron spins in quantum dots inside optical microcavities. Our schemes for these universal quantum gates on a hybrid system have some advantages. First, all the gates are accomplished with a success probability of 100$%$ in principle. Second, our schemes require no additional qubits. Third, the control qubits of the gates are easily manipulated and the target qubits are perfect for storage and processing. Fourth, the gates do not require that the transmission for the uncoupled cavity is balanceable with the reflectance for the coupled cavity, in order to get a high fidelity. Fifth, the devices for the three universal gates work in both the weak coupling and the strong coupling regimes, and they are feasible in experiment.

arXiv:1302.0046•Physical Review A•Feb 6, 2013•134 citations

Universal photonic three-qubit quantum gates with two degrees of freedom assisted by charged quantum dots inside single-sided optical microcavities

Bo-Yang Xia, Cong Cao, Yu‐Hong Han +1 more

Abstract Although universal quantum computation can be realized with two-qubit controlled-not (CNOT) gates and single-qubit rotations, it would be convenient to have resource-efficient and robust multiqubit quantum gates in practical quantum information processing. Here we present two new schemes to determinately implement three-qubit Toffoli gate and Fredkin gate on photon systems with two degrees of freedom (DOFs), assisted by charged quantum dots (QDs) inside single-sided optical microcavities. In contrast to the traditional Toffoli and Fredkin gates operating in photonic one DOF, the gates presented here with two DOFs can reduce the photon numbers required to implement the gate operations. Compared with the ones synthesized by CNOT and single-qubit gates, the present gates can reduce the complexity in experiment. Our schemes exploit the robust giant circular birefringence induced by a single-electron spin in a QD-cavity system, which do not require photon indistinguishability or photon interference as demanded by other schemes using linear optics. Moreover, additional ancillary photons are not required in the schemes. We discuss the feasibility of our schemes, concluding that they can be realized with current or near-future technologies.

Laser Physics•Jul 3, 2018•28 citations

Refined quantum gates for ΛΛΛ-type atom-photon hybrid systems

Wu, Yi-Ming, Gang Fan, Fang‐Fang Du

High-efficiency quantum information processing is equivalent to the fewest quantum resources and the simplest operations by means of logic qubit gates. Based on the reflection geometry of a single photon interacting with a three-level $Λ$-typle atom-cavity system, we present some refined protocols for realizing controlled-not (CNOT), Fredkin, and Toffoli gates on hybrid systems. The first control qubit of our gates is encoded on a flying photon, and the rest qubits are encoded on the atoms in optical cavity. Moreover, these quantum gates can be extended to the optimal synthesis of multi-qubit CNOT, Fredkin and Toffoli gates with O(n) optical elements without auxiliary photons or atoms. Further, the simplest single-qubit operations are applied to the photon only, which make these logic gates experimentally feasible with current technology.

arXiv:2210.10597•Oct 19, 2022•0 citations

Universal quantum gates on electron-spin qubits with quantum dots inside single-side optical microcavities

Hai‐Rui Wei, Fu‐Guo Deng

We present some compact quantum circuits for a deterministic quantum computing on electron-spin qubits assisted by quantum dots inside single-side optical microcavities, including the CNOT, Toffoli, and Fredkin gates. They are constructed by exploiting the giant optical Faraday rotation induced by a single-electron spin in a quantum dot inside a single-side optical microcavity as a result of cavity quantum electrodynamics. Our universal quantum gates have some advantages. First, all the gates are accomplished with a success probability of 100% in principle. Second, our schemes require no additional electron-spin qubits and they are achieved by some input-output processes of a single photon. Third, our circuits for these gates are simple and economic. Moreover, our devices for these gates work in both the weak coupling and the strong coupling regimes, and they are feasible in experiment.

arXiv:1503.00198•Optics Express•Jan 3, 2014•101 citations

A scheme for quantum logic gate based on coherent-state qubits in cavity QED system

Shi-Qing Tang, Shunlong Luo, Jiayi Xu

A two-qubit quantum swap gate scheme based on coherent state qubit is proposed in cavity quantum electrodynamics system. Our scheme adopt the interaction between the Λ-type atomic ensemble and the two-mode optical cavity, and the swap gate can be realized directly only one step, so as to save a lot of quantum resources and reduce the number of single qubit rotation operations in the actual quantum information processing. It is found that under the condition of large detuning limit, the excited states of atoms are adiabatically eliminated, and the decoherence caused by the spontaneous emission of atoms is effectively suppressed. All atoms in the optical cavity are universally addressed, which reduces the experimental operation difficulty of the scheme. The fidelity of the quantum logic gate is maintained at a very high level when the photon loss of the cavity field is considered. Compared with the single-atom scheme, it is found that the atom-cavity interaction time required by the atomic ensemble scheme is inversely proportional to the number of atoms, so that the speed of the quantum logic gate can be increased by N times. Therefore, in principle, as long as enough atoms interacting with the optical field, an effective coupling of any atom-cavity field can be generated, which is conducive to selecting the appropriate quantum gate operation time in practical operation and effectively avoiding decoherence.

SPIE Conference on Quantum and Nonlinear Optics•Nov 8, 2021•0 citations

Refined Quantum Gates for Λ‐Type Atom‐Photon Hybrid Systems

Fang‐Fang Du, Yi‐Ming Wu, Gang Fan

Abstract High‐efficiency quantum information processing is equivalent to the fewest quantum resources and simplest operations by means of logic qubit gates. Based on the reflection geometry of a single photon interacting with a three‐level Λ‐type atom‐cavity system, the authors present some refined protocols for realizing controlled‐not (CNOT), Fredkin, and Toffoli gates on hybrid systems. The first control qubit of gates is encoded on a flying photon, and the remaining qubits are encoded on the atoms in the optical cavity. Moreover, these quantum gates can be extended to the optimal synthesis of multi‐qubit CNOT, Fredkin, and Toffoli gates with optical elements without auxiliary photons or atoms. Further, the simplest single‐qubit operations are applied to the photon only, which make these logic gates experimentally feasible with current technology.

Advanced Quantum Technologies•Jul 3, 2023•27 citations
Both cavity quantum electrodynamics and photons are promising candidates for quantum information processing. Here we present two efficient schemes for universal quantum gates, that is, Fredkin gates and SWAP gates on atomic systems, assisted by Faraday rotation catalyzed by an auxiliary single photon. These gates are achieved by successfully reflecting an auxiliary single photon from an optical cavity with a single-trapped atom. They do not require additional qubits and they only need some linear-optical elements besides the nonlinear interaction between the flying photon and the atoms in the optical cavities. Moreover, these two universal quantum gates are robust. A high fidelity can be achieved in our schemes with current experimental technology. They may be very useful in quantum information processing in future, with the great progress on controlling atomic systems.
We present some deterministic schemes to construct universal quantum gates, that is, controlled- not, three-qubit Toffoli, and Fredkin gates, between flying photon qubits and stationary electron-spin qubits assisted by quantum dots inside double-sided optical microcavities. The control qubit of our gates is encoded on the polarization of the moving single photon and the target qubits are encoded on the confined electron spins in quantum dots inside optical microcavities. Our schemes for these universal quantum gates on a hybrid system have some advantages. First, all the gates are accomplished with a success probability of 100% in principle. Second, our schemes require no additional qubits. Third, the control qubits of the gates are easily manipulated and the target qubits are perfect for storage and processing. Fourth, the gates do not require that the transmission for the uncoupled cavity is balanceable with the reflectance for the coupled cavity, in order to get a high fidelity. Fifth, the devices for the three universal gates work in both the weak coupling and the strong coupling regimes, and they are feasible in experiment.
Abstract Although universal quantum computation can be realized with two-qubit controlled-not (CNOT) gates and single-qubit rotations, it would be convenient to have resource-efficient and robust multiqubit quantum gates in practical quantum information processing. Here we present two new schemes to determinately implement three-qubit Toffoli gate and Fredkin gate on photon systems with two degrees of freedom (DOFs), assisted by charged quantum dots (QDs) inside single-sided optical microcavities. In contrast to the traditional Toffoli and Fredkin gates operating in photonic one DOF, the gates presented here with two DOFs can reduce the photon numbers required to implement the gate operations. Compared with the ones synthesized by CNOT and single-qubit gates, the present gates can reduce the complexity in experiment. Our schemes exploit the robust giant circular birefringence induced by a single-electron spin in a QD-cavity system, which do not require photon indistinguishability or photon interference as demanded by other schemes using linear optics. Moreover, additional ancillary photons are not required in the schemes. We discuss the feasibility of our schemes, concluding that they can be realized with current or near-future technologies.
High-efficiency quantum information processing is equivalent to the fewest quantum resources and the simplest operations by means of logic qubit gates. Based on the reflection geometry of a single photon interacting with a three-level ΛΛΛ-typle atom-cavity system, we present some refined protocols for realizing controlled-not (CNOT), Fredkin, and Toffoli gates on hybrid systems. The first control qubit of our gates is encoded on a flying photon, and the rest qubits are encoded on the atoms in optical cavity. Moreover, these quantum gates can be extended to the optimal synthesis of multi-qubit CNOT, Fredkin and Toffoli gates with O(n) optical elements without auxiliary photons or atoms. Further, the simplest single-qubit operations are applied to the photon only, which make these logic gates experimentally feasible with current technology.
We present some compact quantum circuits for a deterministic quantum computing on electron-spin qubits assisted by quantum dots inside single-side optical microcavities, including the CNOT, Toffoli, and Fredkin gates. They are constructed by exploiting the giant optical Faraday rotation induced by a single-electron spin in a quantum dot inside a single-side optical microcavity as a result of cavity quantum electrodynamics. Our universal quantum gates have some advantages. First, all the gates are accomplished with a success probability of 100% in principle. Second, our schemes require no additional electron-spin qubits and they are achieved by some input-output processes of a single photon. Third, our circuits for these gates are simple and economic. Moreover, our devices for these gates work in both the weak coupling and the strong coupling regimes, and they are feasible in experiment.
A two-qubit quantum swap gate scheme based on coherent state qubit is proposed in cavity quantum electrodynamics system. Our scheme adopt the interaction between the Λ-type atomic ensemble and the two-mode optical cavity, and the swap gate can be realized directly only one step, so as to save a lot of quantum resources and reduce the number of single qubit rotation operations in the actual quantum information processing. It is found that under the condition of large detuning limit, the excited states of atoms are adiabatically eliminated, and the decoherence caused by the spontaneous emission of atoms is effectively suppressed. All atoms in the optical cavity are universally addressed, which reduces the experimental operation difficulty of the scheme. The fidelity of the quantum logic gate is maintained at a very high level when the photon loss of the cavity field is considered. Compared with the single-atom scheme, it is found that the atom-cavity interaction time required by the atomic ensemble scheme is inversely proportional to the number of atoms, so that the speed of the quantum logic gate can be increased by N times. Therefore, in principle, as long as enough atoms interacting with the optical field, an effective coupling of any atom-cavity field can be generated, which is conducive to selecting the appropriate quantum gate operation time in practical operation and effectively avoiding decoherence.
Abstract High‐efficiency quantum information processing is equivalent to the fewest quantum resources and simplest operations by means of logic qubit gates. Based on the reflection geometry of a single photon interacting with a three‐level Λ‐type atom‐cavity system, the authors present some refined protocols for realizing controlled‐not (CNOT), Fredkin, and Toffoli gates on hybrid systems. The first control qubit of gates is encoded on a flying photon, and the remaining qubits are encoded on the atoms in the optical cavity. Moreover, these quantum gates can be extended to the optimal synthesis of multi‐qubit CNOT, Fredkin, and Toffoli gates with optical elements without auxiliary photons or atoms. Further, the simplest single‐qubit operations are applied to the photon only, which make these logic gates experimentally feasible with current technology.