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:2211.03597 · Physical Review Applied

Quantum repeaters and teleportation via entangled phase-modulated multimode coherent states

R. Goncharov, Alexei D. Kiselev, E. S. Moiseev, E.O. Samsonov, Sergey A. Moiseev, Fedor Dmitrievich Kiselev, V. I. Egorov

Published Oct 11, 2023• 11 citations
arXivHTMLPDF

Abstract

We present a scheme of quantum repeater that uses entangled multimode coherent states that are obtained by electro-optic modulation of symmetric and antisymmetric Schr\"odinger cat states. Part of the generated entangled frequency modes is sent to a symmetric beam splitter at the central node, while the remaining modes are stored locally in quantum memories. The entangled coherent states between remote quantum memories are conditionally prepared by photon-counting measurements at the output channels of the beam splitter. We study how the effects of decoherence in the quantum channel affect statistics of photocounts and, for the heralding outcomes determined by the parity of photocounts, evaluate the probability of success and the fidelity of the prepared entanglement depending on the symmetry of input cat states. It is demonstrated that the generated entanglement can be employed for teleportation of the phase information from the modulated states that are utilized in quantum key distributions with subcarrier wave encoding.

DOI
10.1103/physrevapplied.20.044030

Related papers

Performance of Quantum Repeaters Using Multimode Schrödinger Cat States

R. Goncharov, Alexei D. Kiselev, V. I. Egorov

Abstract We analyze the performance of quantum repeaters where the protocols of entanglement generation and swapping are based on multimode optical Schrödinger cat states produced using electro-optic modulation of single-mode optical cats. We employ both the mean-only approximation and exact results to calculate the distance dependencies of the mean waiting time and the repeater rate depending on the number of elementary links. The results are compared with the rates of quantum repeater schemes based on photon pairs generated via spontaneous parametric down-conversion.

Bulletin of the Russian Academy of Sciences Physics•Jun 1, 2024•0 citations

Linear-optical teleportation of bipartite entangled coherent states via maximally entangled coherent channels

Shivani A. Kumar

This paper outlines a linear-optical protocol for the teleportation of bipartite entangled coherent states (ECSs) using maximally ECSs as quantum channels. The scheme relies on symmetric beam splitters, phase shifters, photon-number-resolved measurements, and conditional local phase operations. Successful teleportation is achieved probabilistically with a constant success rate of 50%, independent of the coherent-state amplitude [Formula: see text], and governed by the parity of the measurement outcomes. The absence of nonlinear optical processes or direct photon interactions renders the protocol experimentally feasible and scalable, making it suitable for applications in continuous-variable quantum communication, quantum information processing, and coherent-state entanglement distribution.

Modern Physics Letters A•Apr 8, 2026•0 citations

Quantum repeaters with entangled coherent states

Nicolas Sangouard, Christoph Simon, Nicolas Gisin +3 more

Entangled coherent states can be prepared remotely by subtracting nonlocally a single photon from two quantum superpositions of coherent states, the so-called “Schrödinger’s cat” state. Such entanglement can further be distributed over longer distances by successive entanglement swapping operations using linear optics and photon-number resolving detectors. The aim of this paper is to evaluate the performance of this approach to quantum repeaters for long-distance quantum communications. Despite many attractive features at first sight, we show that, when using state-of-the-art photon counters and quantum memories, they do not achieve higher entanglement generation rates than repeaters based on single-photon entanglement. We discuss potential developments, which may take better advantage of the richness of entanglement based on continuous variables, including in particular efficient parity measurements.

arXiv:0912.3871•Journal of the Optical Society of America B•May 3, 2010•98 citations

Quantum teleportation of entangled coherent states

Xiaoguang Wang

We propose a simple scheme for the quantum teleportation of both bipartite and multipartite entangled coherent states with the success probability 1/2. The scheme is based only on linear optical devices such as beam splitters and phase shifters, and two-mode photon number measurements. The quantum channels described by the multipartite maximally entangled coherent states, are readily made by the beam splitters and phase shifters.

arXiv:quant-ph/0102048•Physical Review A•Jul 3, 2001•236 citations

Unidirectional Cyclic Quantum Teleportation of Arbitrary Schrodinger Cat Coherent-states via Bell Coherent-States

Pathak, Ankita, Ravi Shankar Singh

Exploiting the cluster of three Bell coherent-states as quantum channel, we presented a scheme wherein quantum-informations encoded in three arbitrary superposed coherent states, i.e., Schrodinger Cat coherent-states are simultaneously transmitted in unidirectional cyclic sequence among three parties by invoking usage of linear optical gadgets such as ideal beam-splitters, phase shifters and photon-number-resolving detectors. Proposed simultaneous unidirectional Cyclic Quantum Teleportation is faithful with one-eighth probability of success. Furthermore, it is seen that not every detection-events provides faithful scheme and, hence, fidelity and probability of success of near-faithful Cyclic Quantum Teleportation is evaluated and numerically interpreted.

arXiv:2403.02357•Mar 3, 2024•0 citations

Memoryless Quantum Repeaters Based on Cavity‐QED and Coherent States

Pei‐Zhe Li, Peter van Loock

Abstract A quantum repeater scheme based on cavity‐quantum electrodynamics (QED) and quantum error correction of channel loss via rotation‐symmetric bosonic codes (RSBCs) is proposed to distribute atomic entangled states over long distances without memories and at high clock rates. In this scheme, controlled rotation gates, i.e., phase shifts of the propagating light modes conditioned upon the state of an atom placed in a cavity, provide a mechanism both for the entangled‐state preparations and for the error syndrome identifications. In order to assess the performance of this repeater protocol, an explicit instance of RSBCs—multicomponent cat codes—are studied quantitatively. It is found that the total fidelity and the success probability for quantum communication over a long distance (such as 1000 km) both can almost approach unity provided a small enough elementary distance between stations (smaller than 0.1 or 0.01 km) and rather low local losses (up to 0.1%) are considered. In a quantum key distribution application, secret key rates can become correspondingly high, both per channel use, beating the repeaterless bound, and per second thanks to the relatively high clock rates of the memoryless scheme. Based upon the cavity‐QED setting, this scheme can be realized at room temperature and at optical frequencies.

arXiv:2207.02443•Advanced Quantum Technologies•Jun 8, 2023•18 citations
We present a scheme of quantum repeater that uses entangled multimode coherent states that are obtained by electro-optic modulation of symmetric and antisymmetric Schr"odinger cat states. Part of the generated entangled frequency modes is sent to a symmetric beam splitter at the central node, while the remaining modes are stored locally in quantum memories. The entangled coherent states between remote quantum memories are conditionally prepared by photon-counting measurements at the output channels of the beam splitter. We study how the effects of decoherence in the quantum channel affect statistics of photocounts and, for the heralding outcomes determined by the parity of photocounts, evaluate the probability of success and the fidelity of the prepared entanglement depending on the symmetry of input cat states. It is demonstrated that the generated entanglement can be employed for teleportation of the phase information from the modulated states that are utilized in quantum key distributions with subcarrier wave encoding.
Abstract We analyze the performance of quantum repeaters where the protocols of entanglement generation and swapping are based on multimode optical Schrödinger cat states produced using electro-optic modulation of single-mode optical cats. We employ both the mean-only approximation and exact results to calculate the distance dependencies of the mean waiting time and the repeater rate depending on the number of elementary links. The results are compared with the rates of quantum repeater schemes based on photon pairs generated via spontaneous parametric down-conversion.
This paper outlines a linear-optical protocol for the teleportation of bipartite entangled coherent states (ECSs) using maximally ECSs as quantum channels. The scheme relies on symmetric beam splitters, phase shifters, photon-number-resolved measurements, and conditional local phase operations. Successful teleportation is achieved probabilistically with a constant success rate of 50%, independent of the coherent-state amplitude [Formula: see text], and governed by the parity of the measurement outcomes. The absence of nonlinear optical processes or direct photon interactions renders the protocol experimentally feasible and scalable, making it suitable for applications in continuous-variable quantum communication, quantum information processing, and coherent-state entanglement distribution.
Entangled coherent states can be prepared remotely by subtracting nonlocally a single photon from two quantum superpositions of coherent states, the so-called “Schrödinger’s cat” state. Such entanglement can further be distributed over longer distances by successive entanglement swapping operations using linear optics and photon-number resolving detectors. The aim of this paper is to evaluate the performance of this approach to quantum repeaters for long-distance quantum communications. Despite many attractive features at first sight, we show that, when using state-of-the-art photon counters and quantum memories, they do not achieve higher entanglement generation rates than repeaters based on single-photon entanglement. We discuss potential developments, which may take better advantage of the richness of entanglement based on continuous variables, including in particular efficient parity measurements.
Exploiting the cluster of three Bell coherent-states as quantum channel, we presented a scheme wherein quantum-informations encoded in three arbitrary superposed coherent states, i.e., Schrodinger Cat coherent-states are simultaneously transmitted in unidirectional cyclic sequence among three parties by invoking usage of linear optical gadgets such as ideal beam-splitters, phase shifters and photon-number-resolving detectors. Proposed simultaneous unidirectional Cyclic Quantum Teleportation is faithful with one-eighth probability of success. Furthermore, it is seen that not every detection-events provides faithful scheme and, hence, fidelity and probability of success of near-faithful Cyclic Quantum Teleportation is evaluated and numerically interpreted.
Abstract A quantum repeater scheme based on cavity‐quantum electrodynamics (QED) and quantum error correction of channel loss via rotation‐symmetric bosonic codes (RSBCs) is proposed to distribute atomic entangled states over long distances without memories and at high clock rates. In this scheme, controlled rotation gates, i.e., phase shifts of the propagating light modes conditioned upon the state of an atom placed in a cavity, provide a mechanism both for the entangled‐state preparations and for the error syndrome identifications. In order to assess the performance of this repeater protocol, an explicit instance of RSBCs—multicomponent cat codes—are studied quantitatively. It is found that the total fidelity and the success probability for quantum communication over a long distance (such as 1000 km) both can almost approach unity provided a small enough elementary distance between stations (smaller than 0.1 or 0.01 km) and rather low local losses (up to 0.1%) are considered. In a quantum key distribution application, secret key rates can become correspondingly high, both per channel use, beating the repeaterless bound, and per second thanks to the relatively high clock rates of the memoryless scheme. Based upon the cavity‐QED setting, this scheme can be realized at room temperature and at optical frequencies.