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

AIP Advances

General phase-covariant quantum cloning

Lan-Lan Li, Wen‐Hai Zhang, Ke Zhang, Cheng-Yu Fan

Published Dec 1, 2024• 0 citations
Publisher

Abstract

Phase-covariant quantum cloning has important applications in quantum cryptography. This paper proposes the unitary transformation of the optimal 1 → 2 general phase covariant quantum cloning in two dimensions and obtains the maximal fidelity of copies. In addition, an experimental scheme is designed to implement this unitary transformation using linear optical elements, and the scheme is feasible under the present experimental technology.

DOI
10.1063/5.0244043

Related papers

Realization of the optimal phase-covariant quantum cloning machine

Fabio Sciarrino, F. De Martini

In several quantum information (QI) phenomena of large technological importance the information is carried by the phase of the quantum superposition states, or qubits. The phase-covariant cloning machine (PQCM) addresses precisely the problem of optimally copying these qubits with the largest attainable ``fidelity.'' We present a general scheme which realizes the $1\ensuremath{\rightarrow}3$ phase covariant cloning process by a combination of three different QI processes: the universal cloning, the NOT gate, and the projection over the symmetric subspace of the output qubits. The experimental implementation of a PQCM for polarization encoded qubits, the first ever realized with photons, is reported.

arXiv:quant-ph/0412041•Physical Review A•Dec 9, 2005•48 citations

OPTICAL IMPLEMENTATION OF THE OPTIMAL UNIVERSAL AND PHASE-COVARIANT QUANTUM CLONING MACHINES

Liu Ye, Xue‐Ke Song, JIE YANG +2 more

Quantum cloning relates to the security of quantum computation and quantum communication. In this paper, firstly we propose a feasible unified scheme to implement optimal 1 → 2 universal, 1 → 2 asymmetric and symmetric phase-covariant cloning, and 1 → 2 economical phase-covariant quantum cloning machines only via a beam splitter. Then 1 → 3 economical phase-covariant quantum cloning machines also can be realized by adding another beam splitter in context of linear optics. The scheme is based on the interference of two photons on a beam splitter with different splitting ratios for vertical and horizontal polarization components. It is shown that under certain condition, the scheme is feasible by current experimental technology.

Modern Physics Letters B•May 28, 2012•1 citation

Optical realization of optimal symmetric universal and phase-covariant quantum cloning

Qing-Min Song, Bao‐Long Fang, Tao Wu +1 more

We propose an experimentally unified linear optical scheme to implement the optimal symmetric one to two (1 → 2) universal, optimal symmetric 1 → 2 phase-covariant and optimal symmetric economical one to three (1 → 3) phase-covariant quantum cloning machines of the polarization state of the single photon. This scheme requires single-photon sources as the input state. Here, we use a laser beam attenuated to the single-photon level as the input source. The scheme relies on one polarized qubit and two location qubits and it also involves linear optical elements. It is shown that under certain conditions, the scheme is feasible by current experimental technology.

Journal of Modern Optics•Jan 18, 2011•0 citations

PROPOSAL FOR A GENERAL QUANTUM CLONING MACHINE VIA DISTANT QUBITS IN A QUANTUM NETWORK

Yang Yu, Ye Liu

We propose a scheme for implementing a general quantum cloning machine with distant qubits. By regulating some times and phases, we can easily realize almost all kinds of quantum cloning machines (optimal phase-covariant cloning, optimal universal quantum cloning, optimal economical phase-covariant cloning and optimal real state cloning). The quantum cloning machine may have important applications in quantum cryptography for quantum network.

International Journal of Modern Physics B•Aug 13, 2013•1 citation

Implementation of optimal phase-covariant cloning machines

Fabio Sciarrino, F. De Martini

The optimal phase-covariant quantum cloning machine (PQCM) broadcasts the information associated to an input qubit into a multiqubit system, exploiting a partial a priori knowledge of the input state. This additional a priori information leads to a higher fidelity than for the universal cloning. The present article first analyzes different innovative schemes to implement the $1\ensuremath{\rightarrow}3$ PQCM. The method is then generalized to any $1\ensuremath{\rightarrow}M$ machine for an odd value of $M$ by a theoretical approach based on the general angular momentum formalism. Finally different experimental schemes based either on linear or nonlinear methods and valid for single photon polarization encoded qubits are discussed.

arXiv:quant-ph/0609105•Physical Review A•Jul 26, 2007•21 citations

Phase-covariant quantum cloning of qudits

Heng Fan, Hiroshi Imai, Keiji Matsumoto +1 more

We study the phase-covariant quantum cloning machine for qudits, i.e., the input states in a d-level quantum system have complex coefficients with arbitrary phase but constant module. A cloning unitary transformation is proposed. After optimizing the fidelity between input state and single qudit reduced density operator of output state, we obtain the optimal fidelity for 1 to 2 phase-covariant quantum cloning of qudits and the corresponding cloning transformation.

arXiv:quant-ph/0205126•Physical Review A•Feb 28, 2003•115 citations
Phase-covariant quantum cloning has important applications in quantum cryptography. This paper proposes the unitary transformation of the optimal 1 → 2 general phase covariant quantum cloning in two dimensions and obtains the maximal fidelity of copies. In addition, an experimental scheme is designed to implement this unitary transformation using linear optical elements, and the scheme is feasible under the present experimental technology.
In several quantum information (QI) phenomena of large technological importance the information is carried by the phase of the quantum superposition states, or qubits. The phase-covariant cloning machine (PQCM) addresses precisely the problem of optimally copying these qubits with the largest attainable ``fidelity.'' We present a general scheme which realizes the $1\ensuremath{\rightarrow}3$ phase covariant cloning process by a combination of three different QI processes: the universal cloning, the NOT gate, and the projection over the symmetric subspace of the output qubits. The experimental implementation of a PQCM for polarization encoded qubits, the first ever realized with photons, is reported.
Quantum cloning relates to the security of quantum computation and quantum communication. In this paper, firstly we propose a feasible unified scheme to implement optimal 1 → 2 universal, 1 → 2 asymmetric and symmetric phase-covariant cloning, and 1 → 2 economical phase-covariant quantum cloning machines only via a beam splitter. Then 1 → 3 economical phase-covariant quantum cloning machines also can be realized by adding another beam splitter in context of linear optics. The scheme is based on the interference of two photons on a beam splitter with different splitting ratios for vertical and horizontal polarization components. It is shown that under certain condition, the scheme is feasible by current experimental technology.
We propose an experimentally unified linear optical scheme to implement the optimal symmetric one to two (1 → 2) universal, optimal symmetric 1 → 2 phase-covariant and optimal symmetric economical one to three (1 → 3) phase-covariant quantum cloning machines of the polarization state of the single photon. This scheme requires single-photon sources as the input state. Here, we use a laser beam attenuated to the single-photon level as the input source. The scheme relies on one polarized qubit and two location qubits and it also involves linear optical elements. It is shown that under certain conditions, the scheme is feasible by current experimental technology.
The optimal phase-covariant quantum cloning machine (PQCM) broadcasts the information associated to an input qubit into a multiqubit system, exploiting a partial a priori knowledge of the input state. This additional a priori information leads to a higher fidelity than for the universal cloning. The present article first analyzes different innovative schemes to implement the $1\ensuremath{\rightarrow}3$ PQCM. The method is then generalized to any $1\ensuremath{\rightarrow}M$ machine for an odd value of MMM by a theoretical approach based on the general angular momentum formalism. Finally different experimental schemes based either on linear or nonlinear methods and valid for single photon polarization encoded qubits are discussed.