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

arXiv:1410.3047 · Physical Review B

One-step transfer or exchange of arbitrary multipartite quantum states with a single-qubit coupler

Chui‐Ping Yang, Qi-Ping Su, Shi‐Biao Zheng, Siyuan Han

Published Aug 18, 2015• 11 citations
arXivHTMLPDF

Abstract

The transfer or exchange of multipartite quantum states is critical to the realization of large-scale quantum information processing and quantum communication. In this work, we demonstrate that by using a single quantum two-level system---a qubit---as a coupler, arbitrary multipartite quantum states (either entangled or separable) can be transferred or exchanged simultaneously between two sets of qubits. During the entire process, the coupler remains unexcited minimizing the effect of coupler decoherence on the process. This feature allows one to use qubits with rapid frequency tunability and a large range of frequency tuning, such as phase qubits, as couplers. Our findings offer the potential to significantly reduce the resources needed to construct and operate large-scale quantum information networks consisting of many multiqubit registers, memory cells, and processing units.

DOI
10.1103/physrevb.92.054509

Related papers

Simultaneous quantum state exchange or transfer between two sets of cavities and generation of multiple Einstein-Podolsky-Rosen pairs via a superconducting coupler qubit

Chui‐Ping Yang, Qi-Ping Su, Shi-Biao Zheng +1 more

We propose an approach to simultaneously perform quantum state exchange or transfer between two sets of cavities, each containing $N$ cavities, by using only one superconducting coupler qubit. The quantum states to be exchanged or transferred can be arbitrary pure or mixed states and entangled or nonentangled. The operation time does not increase with the number of cavities, and there is no need of applying classic pulses during the entire operation. Moreover, the approach can be also applied to realize quantum state exchange or transfer between two sets of qubits, such as that between two multi-qubit quantum registers. We further show that the present proposal can be used to simultaneously generate multiple Einstein-Podolsky-Rosen pairs of photons or qubits, which are important in quantum communication. The method can be generalized to other systems by using different types of physical qubit as a coupler to accomplish the same task.

arXiv:1305.7472•May 31, 2013•0 citations

Fast and perfect state transfer in superconducting circuit with tunable coupler

Chi 驰 Zhang 张, Tian-Le Wang, Ze-An 泽安 Zhao 赵 +5 more

In quantum computation and quantum information processing, the manipulation and engineering of quantum systems to suit certain purposes are an ongoing task. One such example is quantum state transfer (QST), an essential requirement for both quantum communication and large-scale quantum computation. Here we engineer a chain of four superconducting qubits with tunable couplers to realize the perfect state transfer (PST) protocol originally proposed in quantum spin networks and successfully demonstrate the efficient transfer of an arbitrary single-qubit state from one end of the chain to the other, achieving a high fidelity of 0.986 in just 25 ns. This demonstrated QST is readily to extend to larger chain and multi-node configurations, thus serving as a desirable tool for scalable quantum information processing.

Chinese Physics B•Aug 29, 2023•6 citations

Entanglement generation and quantum information transfer between spatially-separated qubits in different cavities

Chui‐Ping Yang, Qi-Ping Su, Franco Nori

The generation and control of quantum states of spatially-separated qubits distributed in different cavities constitute fundamental tasks in cavity quantum electrodynamics (QED). An interesting question in this context is how to prepare entanglement and realize quantum information transfer between qubits located at different cavities, which are important in large-scale quantum information processing. In this paper, we consider a physical system consisting of two cavities and three qubits. Two of the qubits are placed in two different cavities while the remaining one acts as a coupler, which is used to connect the two cavities. We propose an approach for generating quantum entanglement and implementing quantum information transfer between the two spatially-separated inter-cavity qubits. The quantum operations involved in this proposal are performed by a virtual photon process; thus the cavity decay is greatly suppressed during operations. In addition, to complete these tasks, only one coupler qubit and one operation step are needed. Moreover, there is no need to apply classical pulses, so that the engineering complexity is much reduced and the operation procedure is greatly simplified. Finally, our numerical results illustrate that high-fidelity implementation of this proposal using superconducting phase qubits and one-dimensional transmission line resonators is feasible for current circuit QED implementations. This proposal can also be applied to other types of superconducting qubits, including flux and charge qubits.

arXiv:1307.2503•New Journal of Physics•Nov 1, 2013•40 citations

Enhanced quantum state transfer by circumventing quantum chaotic behavior

Liang Xiang, Jiachen Chen, Zitian Zhu +16 more

The ability to realize high-fidelity quantum communication is one of the many facets required to build generic quantum computing devices. In addition to quantum processing, sensing, and storage, transferring the resulting quantum states demands a careful design that finds no parallel in classical communication. Existing experimental demonstrations of quantum information transfer in solid-state quantum systems are largely confined to small chains with few qubits, often relying upon non-generic schemes. Here, by using a superconducting quantum circuit featuring thirty-six tunable qubits, accompanied by general optimization procedures deeply rooted in overcoming quantum chaotic behavior, we demonstrate a scalable protocol for transferring few-particle quantum states in a two-dimensional quantum network. These include single-qubit excitation, two-qubit entangled states, and two excitations for which many-body effects are present. Our approach, combined with the quantum circuit's versatility, paves the way to short-distance quantum communication for connecting distributed quantum processors or registers, even if hampered by inherent imperfections in actual quantum devices.

arXiv:2402.00936•Nature Communications•Jun 10, 2024•28 citations

Transferring entangled states of photonic cat-state qubits in circuit QED

Tong Liu, Zhen-Fei Zheng, Yu Zhang +2 more

We propose a method for transferring quantum entangled states of two photonic cat-state qubits ( cqubits ) from two microwave cavities to the other two microwave cavities. This proposal is realized by using four microwave cavities coupled to a superconducting flux qutrit. Because of using four cavities with different frequencies, the inter-cavity crosstalk is significantly reduced. Since only one coupler qutrit is used, the circuit resource is minimized. The entanglement transfer is completed with a singlestep operation only, thus this proposal is quite simple. The third energy level of the coupler qutrit is not populated during the state transfer, therefore decoherence from the higher energy level is greatly suppressed. Our numerical simulations show that high-fidelity transfer of two- cqubit entangled states from two transmission line resonators to the other two transmission line resonators is feasible with current circuit QED technology. This proposal is universal and can be applied to accomplish the same task in a wide range of physical systems, such as four microwave or optical cavities, which are coupled to a natural or artificial three-level atom.

arXiv:2003.14168•Frontiers of Physics•Jan 13, 2020•13 citations

1 A Simple Scheme to Entangle Distant Qubits from a Mixed State via an Entanglement Mediator

Kazuya Yuasa, Hiromichi Nakazato

A simple scheme to prepare an entanglement between two separated qubits from a given mixed state is proposed. A single qubit (entanglement mediator) is repeatedly made to interact locally and consecutively with the two qubits through rotating-wave couplings and is then measured. It is shown that we need to repeat this kind of process only three times to establish a maximally entangled state directly from an arbitrary initial mixed state, with no need to prepare the state of the qubits in advance or to rearrange the setup step by step. Furthermore, the maximum yield realizable with this scheme is compatible with the maximum entanglement, provided that the coupling constants are properly tuned. Entanglement is one of the peculiar concepts in quantum physics. It shows a nonlocal property of quantum mechanics, and is the essence of nonclassical phenomena. This concept is now regarded as a key to moving beyond classical ideas and plays a central role in the field of quantum information and computation. 1),2) The peculiarity of entanglement reveals itself especially when it involves spatially separated systems. Nonlocality has been studied in such situations, 3) and such an entanglement is of fundamental importance in quantum communication, for example,

•Jan 1, 2004•6 citations
The transfer or exchange of multipartite quantum states is critical to the realization of large-scale quantum information processing and quantum communication. In this work, we demonstrate that by using a single quantum two-level system---a qubit---as a coupler, arbitrary multipartite quantum states (either entangled or separable) can be transferred or exchanged simultaneously between two sets of qubits. During the entire process, the coupler remains unexcited minimizing the effect of coupler decoherence on the process. This feature allows one to use qubits with rapid frequency tunability and a large range of frequency tuning, such as phase qubits, as couplers. Our findings offer the potential to significantly reduce the resources needed to construct and operate large-scale quantum information networks consisting of many multiqubit registers, memory cells, and processing units.
We propose an approach to simultaneously perform quantum state exchange or transfer between two sets of cavities, each containing NNN cavities, by using only one superconducting coupler qubit. The quantum states to be exchanged or transferred can be arbitrary pure or mixed states and entangled or nonentangled. The operation time does not increase with the number of cavities, and there is no need of applying classic pulses during the entire operation. Moreover, the approach can be also applied to realize quantum state exchange or transfer between two sets of qubits, such as that between two multi-qubit quantum registers. We further show that the present proposal can be used to simultaneously generate multiple Einstein-Podolsky-Rosen pairs of photons or qubits, which are important in quantum communication. The method can be generalized to other systems by using different types of physical qubit as a coupler to accomplish the same task.
In quantum computation and quantum information processing, the manipulation and engineering of quantum systems to suit certain purposes are an ongoing task. One such example is quantum state transfer (QST), an essential requirement for both quantum communication and large-scale quantum computation. Here we engineer a chain of four superconducting qubits with tunable couplers to realize the perfect state transfer (PST) protocol originally proposed in quantum spin networks and successfully demonstrate the efficient transfer of an arbitrary single-qubit state from one end of the chain to the other, achieving a high fidelity of 0.986 in just 25 ns. This demonstrated QST is readily to extend to larger chain and multi-node configurations, thus serving as a desirable tool for scalable quantum information processing.
The generation and control of quantum states of spatially-separated qubits distributed in different cavities constitute fundamental tasks in cavity quantum electrodynamics (QED). An interesting question in this context is how to prepare entanglement and realize quantum information transfer between qubits located at different cavities, which are important in large-scale quantum information processing. In this paper, we consider a physical system consisting of two cavities and three qubits. Two of the qubits are placed in two different cavities while the remaining one acts as a coupler, which is used to connect the two cavities. We propose an approach for generating quantum entanglement and implementing quantum information transfer between the two spatially-separated inter-cavity qubits. The quantum operations involved in this proposal are performed by a virtual photon process; thus the cavity decay is greatly suppressed during operations. In addition, to complete these tasks, only one coupler qubit and one operation step are needed. Moreover, there is no need to apply classical pulses, so that the engineering complexity is much reduced and the operation procedure is greatly simplified. Finally, our numerical results illustrate that high-fidelity implementation of this proposal using superconducting phase qubits and one-dimensional transmission line resonators is feasible for current circuit QED implementations. This proposal can also be applied to other types of superconducting qubits, including flux and charge qubits.
The ability to realize high-fidelity quantum communication is one of the many facets required to build generic quantum computing devices. In addition to quantum processing, sensing, and storage, transferring the resulting quantum states demands a careful design that finds no parallel in classical communication. Existing experimental demonstrations of quantum information transfer in solid-state quantum systems are largely confined to small chains with few qubits, often relying upon non-generic schemes. Here, by using a superconducting quantum circuit featuring thirty-six tunable qubits, accompanied by general optimization procedures deeply rooted in overcoming quantum chaotic behavior, we demonstrate a scalable protocol for transferring few-particle quantum states in a two-dimensional quantum network. These include single-qubit excitation, two-qubit entangled states, and two excitations for which many-body effects are present. Our approach, combined with the quantum circuit's versatility, paves the way to short-distance quantum communication for connecting distributed quantum processors or registers, even if hampered by inherent imperfections in actual quantum devices.
We propose a method for transferring quantum entangled states of two photonic cat-state qubits ( cqubits ) from two microwave cavities to the other two microwave cavities. This proposal is realized by using four microwave cavities coupled to a superconducting flux qutrit. Because of using four cavities with different frequencies, the inter-cavity crosstalk is significantly reduced. Since only one coupler qutrit is used, the circuit resource is minimized. The entanglement transfer is completed with a singlestep operation only, thus this proposal is quite simple. The third energy level of the coupler qutrit is not populated during the state transfer, therefore decoherence from the higher energy level is greatly suppressed. Our numerical simulations show that high-fidelity transfer of two- cqubit entangled states from two transmission line resonators to the other two transmission line resonators is feasible with current circuit QED technology. This proposal is universal and can be applied to accomplish the same task in a wide range of physical systems, such as four microwave or optical cavities, which are coupled to a natural or artificial three-level atom.
A simple scheme to prepare an entanglement between two separated qubits from a given mixed state is proposed. A single qubit (entanglement mediator) is repeatedly made to interact locally and consecutively with the two qubits through rotating-wave couplings and is then measured. It is shown that we need to repeat this kind of process only three times to establish a maximally entangled state directly from an arbitrary initial mixed state, with no need to prepare the state of the qubits in advance or to rearrange the setup step by step. Furthermore, the maximum yield realizable with this scheme is compatible with the maximum entanglement, provided that the coupling constants are properly tuned. Entanglement is one of the peculiar concepts in quantum physics. It shows a nonlocal property of quantum mechanics, and is the essence of nonclassical phenomena. This concept is now regarded as a key to moving beyond classical ideas and plays a central role in the field of quantum information and computation. 1),2) The peculiarity of entanglement reveals itself especially when it involves spatially separated systems. Nonlocality has been studied in such situations, 3) and such an entanglement is of fundamental importance in quantum communication, for example,