In this paper, two conclusive three-party cyclic assisted cloning protocols in amplitude damping (AD) channel are put forward that, respectively clone three arbitrary unknown single-qubit states and single-qutrit states with the help of a state preparer. Each of our protocols includes three consecutive stages: quantum channel preparation, cyclic quantum teleportation (CQT), and multi-party assisted cloning. The first stage of each protocol proposes the detailed processes of sharing a pure entangled quantum state as a component of a quantum channel in AD channel via entanglement compensation. In second stage, a three-party CQT is presented where three unknown single-qubit states (or single-qutrit states) are reconstructed simultaneously in three different places, respectively, by introducing auxiliary qubits and performing appropriate operations. In the third stage, the state preparer Victor performs one multi-qubit measurement (or one unitary transformation and one multi-qutrit measurement) and informs the three communicators of his outcome, three distinct unknown single-qubit states or their orthogonal complement states (or single-qutrit states) are cloned simultaneously and with probability at three separate locations,respectively. Furthermore, we extend the above protocols from two aspects: (i) the extension to the case of [Formula: see text] participants; (ii) extension to the case of d-dimensional unknown single-qudit state cycle-assisted cloning.In this paper, two conclusive three-party cyclic assisted cloning protocols in amplitude damping (AD) channel are put forward that, respectively clone three arbitrary unknown single-qubit states and single-qutrit states with the help of a state preparer. Each of our protocols includes three consecutive stages: quantum channel preparation, cyclic quantum teleportation (CQT), and multi-party assisted cloning. The first stage of each protocol proposes the detailed processes of sharing a pure entangled quantum state as a component of a quantum channel in AD channel via entanglement compensation. In second stage, a three-party CQT is presented where three unknown single-qubit states (or single-qutrit states) are reconstructed simultaneously in three different places, respectively, by introducing auxiliary qubits and performing appropriate operations. In the third stage, the state preparer Victor performs one multi-qubit measurement (or one unitary transformation and one multi-qutrit measurement) and informs the three communicators of his outcome, three distinct unknown single-qubit states or their orthogonal complement states (or single-qutrit states) are cloned simultaneously and with probability at three separate locations,respectively. Furthermore, we extend the above protocols from two aspects: (i) the extension to the case of [Formula: see text] participants; (ii) extension to the case of d-dimensional unknown single-qudit state cycle-assisted cloning.

PLoS ONESep 2, 20250 citations

Relationship Between Entanglement and Coherence in Some Two-Qubit States

Fa Zhao, Dong Wang, Ye Liu

International Journal of Theoretical PhysicsJan 1, 202211 citations

Controlled and assisted cloning of two-, three- and four-qubit states with optimal quantum resources

Nueraminaimu Maihemuti, Peng Jia-yin, Yimamujiang Aisan +1 more

Utilizing Hadamard gates and controlled not gates, maximally entangled states of four, five and six qubits are generated. Then, we propose respectively controlled and assisted cloning schemes of unknown two-, three- and four-qubit states via these constructed states as quantum channels. Each of the three schemes includes two stages: controlled teleportation and assisted cloning. The controlled teleportation stage of our schemes all require a single-qubit [Formula: see text]-basis measurement by controller, and need different GHZ-state measurements by senders of three schemes to complete the transmission process of their respective quantum states. In the assisted cloning stage of our schemes, after the state preparers of three schemes perform respectively appropriate GHZ-state measurements, at the senders’ locations, perfect replicas and orthogonal complementary copies of unknown states will be produced through appropriate local quantum operations. Compared with usual assisted cloning schemes, every suggested plan is extremely efficient in terms of quantum resources, as it only requires a small number of GHZ-state measurements, significantly decreasing the need for quantum operations and classical resources. Through discussion, we conclude that our schemes are safe and can be extended to assisted cloning of unknown multi-qubit GHZ-state with multiple controllers.Utilizing Hadamard gates and controlled not gates, maximally entangled states of four, five and six qubits are generated. Then, we propose respectively controlled and assisted cloning schemes of unknown two-, three- and four-qubit states via these constructed states as quantum channels. Each of the three schemes includes two stages: controlled teleportation and assisted cloning. The controlled teleportation stage of our schemes all require a single-qubit [Formula: see text]-basis measurement by controller, and need different GHZ-state measurements by senders of three schemes to complete the transmission process of their respective quantum states. In the assisted cloning stage of our schemes, after the state preparers of three schemes perform respectively appropriate GHZ-state measurements, at the senders’ locations, perfect replicas and orthogonal complementary copies of unknown states will be produced through appropriate local quantum operations. Compared with usual assisted cloning schemes, every suggested plan is extremely efficient in terms of quantum resources, as it only requires a small number of GHZ-state measurements, significantly decreasing the need for quantum operations and classical resources. Through discussion, we conclude that our schemes are safe and can be extended to assisted cloning of unknown multi-qubit GHZ-state with multiple controllers.

International Journal of Quantum InformationNov 15, 20241 citation

Entanglement of Singlet-Triplet Qubits

Michael Shulman

Bulletin of the American Physical SocietyMar 18, 20130 citations

Broadcasting of quantum correlations in qubit-qudit systems

Rounak Mundra, Dhrumil Patel, Indranil Chakrabarty +2 more

Quantum mechanical properties like entanglement, discord, and coherence act as fundamental resources in various quantum information processing tasks. Consequently, the technique of generating more resources from a few, typically termed as broadcasting, serves as a promising candidate for the design of quantum networks. One way to broadcast resources could be using a cloning operation. In this article, broadcasting of quantum resources beyond $2\ensuremath{\bigotimes}2$ systems is investigated. In particular, in $2\ensuremath{\bigotimes}3$ dimensions, a class of states not useful for broadcasting of entanglement is characterized considering an optimal universal Heisenberg cloning machine. The broadcasting ranges for maximally entangled mixed states and two-parameter class of states are obtained to exemplify our protocol. A significant derivative of our protocol is that the cloning operation generates a qutrit ($3\ensuremath{\bigotimes}3$) entangled pair with positive partial transpose on one of the local sides, and an absolutely separable qubit ($2\ensuremath{\bigotimes}2$) pair on the other side of the input bipartite $2\ensuremath{\bigotimes}3$-dimensional resource state. Moving beyond entanglement, in $2\ensuremath{\bigotimes}d$ dimensions, the impossibility to optimally broadcast quantum discord and quantum coherence ( ${l}_{1}$ norm) is established. However, some significant illustrations are provided to highlight that nonoptimal broadcasting of discord and coherence is still possible.Quantum mechanical properties like entanglement, discord, and coherence act as fundamental resources in various quantum information processing tasks. Consequently, the technique of generating more resources from a few, typically termed as broadcasting, serves as a promising candidate for the design of quantum networks. One way to broadcast resources could be using a cloning operation. In this article, broadcasting of quantum resources beyond $2\ensuremath{\bigotimes}2$ systems is investigated. In particular, in $2\ensuremath{\bigotimes}3$ dimensions, a class of states not useful for broadcasting of entanglement is characterized considering an optimal universal Heisenberg cloning machine. The broadcasting ranges for maximally entangled mixed states and two-parameter class of states are obtained to exemplify our protocol. A significant derivative of our protocol is that the cloning operation generates a qutrit ($3\ensuremath{\bigotimes}3$) entangled pair with positive partial transpose on one of the local sides, and an absolutely separable qubit ($2\ensuremath{\bigotimes}2$) pair on the other side of the input bipartite $2\ensuremath{\bigotimes}3$-dimensional resource state. Moving beyond entanglement, in $2\ensuremath{\bigotimes}d$ dimensions, the impossibility to optimally broadcast quantum discord and quantum coherence (${l}_{1}$ norm) is established. However, some significant illustrations are provided to highlight that nonoptimal broadcasting of discord and coherence is still possible.

arXiv:1807.11002Physical Review AOct 18, 20197 citations

{l}_{1}

norm) is established. However, some significant illustrations are provided to highlight that nonoptimal broadcasting of discord and coherence is still possible.