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

Physical Review Letters

Optical Implementation of Quantum Orienteering

Evan R. Jeffrey, Joseph B. Altepeter, Madalina Colci, Paul G. Kwiat

Published Apr 20, 2006• 11 citations
Publisher

Abstract

We present results from an optical implementation of quantum orienteering, a protocol for communicating directions in space using quantum bits. We show how different types of measurements and encodings can be used to increase the communication efficiency. In particular, if Alice and Bob use two spin- particles for communication and employ joint measurements, they do better than is possible with local operations and classical communication. Furthermore, by using oppositely oriented spins, the achievable communication efficiency is further increased. Finally, we discuss the limitations of an optical approach: our results highlight the usually overlooked nonequivalence of different physical encodings of quantum bits.

DOI
10.1103/physrevlett.96.150503

Related papers

Quantum communication with entanglement

Vlatko Vedral

Abstract This chapter discusses some of the ways in which quantum entanglement can be used for quantum communication. Suppose Alice and Bob share an entangled state: they can use it for dense coding, in which Alice sends Bob just one qubit of an entangled pair, which delivers two bits of classical information. Alice and Bob can also use an entangled state for teleportation, in which a qubit in a unknown quantum state is teleported from Alice to Bob when Alice sends Bob two classical bits. Entanglement swapping is an example of a tripartite communication protocol. If Alice and Bob share entanglement, and Bob and Charlie share entanglement, entanglement swapping can be used to entangle Alice and Charlie. Even if Alice and Bob are entangled, Alice cannot communicate with Bob without sending him classical bits or qubits, which prevents Alice and Bob from breaking the laws of relativity. This chapter also discusses Pauli matrices and the extension of Hilbert spaces.

•Sep 28, 2006•0 citations

Quantum Communication Over Dual-Entanglement Channels Without Dependence on Classical Inter-Party Links

Nipun Agarwal

This paper introduces a protocol for quantum communication that employs entangled and separable pairs of particles, enabling classical information transmission without the need for classical communication between the parties. In this system, one party, Alice, manipulates the entanglement degree of photon pairs within two distinct channels, |ψ⟩ 1 and |ψ⟩ 2. The other party, Bob, subsequently measures the state of these photons. This study uses the entanglement status of each photon pair to encode classical bits: entangled pairs |00⟩ + |11⟩ represent the bit '1', while separable pairs |00⟩ represent '0'. The proposed protocol incorporates a secondary quantum channel that enhances entanglement determination accuracy through additional measurements and phase shifts. The proposed approach stands apart from conventional quantum teleportation, which requires inter-party classical communication, by only requiring an internal classical link at the receiver's end for entanglement status resolution. The proposed method offers benefits when classical communication implementation is impractical or costly. The research highlights the potential of a fully quantum-based communication system, bridging the gap between quantum entanglement and quantum teleportation in a novel, pragmatic manner. While there is a need for improvements to enhance efficiency, security, and reliability, the proposed protocol offers a promising path for future explorations in quantum channel communication.

•Jul 15, 2024•0 citations

Quantum communication

Jonathan A. Jones, Dieter Jaksch

The natural choice of physical qubit for quantum communication is the photon: a photon can be transmitted quickly from the sender to a distant receiver and the technology for creating, manipulating, distributing, and measuring light pulses is well established. Many of these classical techniques can also be employed for quantum communication protocols. We will therefore focus our attention on optical setups for quantum communication. We will study a number of optical setups in the next few sections and use the conventions introduced in Chapter 4 to analyze them. In particular, we will assume that the qubits are encoded in the degrees of freedom of a single photon. Some of the main technical challenges in quantum communication arise from this need to work with single photon pulses. For instance, photons do not interact with each other in vacuum or linear media, and interactions between two photons in non-linear optical media are relatively small, so that realizing entangling two photon gates via coherent interactions is a challenging task. The quantum communication schemes discussed here circumvent this technical problem to a large extent. They only use non-linear optical materials for parametric down-conversion to create Bell-pairs of photons and then exploit standard linear optical devices and photo-detectors to manipulate them. No further non-linear entangling gates are required. Parametric down-conversion In non-linear optical media a single photon can be down-converted into a pair of photons. In this coherent process the incoming photon is destroyed and two photons of lower energy are created.

Cambridge University Press eBooks•Jul 19, 2012•5 citations

Scheme of Quantum Dialogue Based on Four-particle Omega State and Security of Intercept-resend Attack

Yang You-fen

A scheme of quantum dialogue was proposed based on four-particle omega state.First,Bob,a communication party,prepared a four-particle omega state,encoded classical secret information by performing an approprite unitary transformation on two particles of the omega state and sent them to Alice.Then,Alice also performed an approprite unitary transformation on the two particles to encode secret information and sent back to Bob.Finally,Bob made joint measurement to final omega state,and announced the results.Alice and Bob,two parties of communication,could decode classical information the opposite one transfers,according to the announced measurement results and itself unitary operator,making the bidirectional communication come true.The result shows that the communication scheme only transfers two particles and makes unitary operations twice,and two communication parties get the opposite four-bit classcical information.It realizes both two-way communication of classical information with quantum channel and dense encoding to improve the communication capacity.The Eve′s intercept-resend attack can be found in time by inserting decoy photons in the system to raise the security of communication system.

ACTA PHOTONICA SINICA•Jan 1, 2013•0 citations

Controlled Secure Quantum Dialogue by Using Brown States

Yang You-fen

A novel scheme of controlled secure quantum dialogue by using Brown states was proposed in this paper.It this scheme,Alice,Bob and Charlie shared a five-particle Brown states.Alice made unitary operations on two particles of the Brown states to realize encoding her secret calssical message.Similarly,Bob performed corresponding unitary transformations to another two particles to encode the information that he wanted to send to Alice.Later,Charlie made Brown base states joint measurement on the Brown final state and announced the measured results.Alice and Bob deduced the opposite party′s information according to Charlie′s announced measurement results and her(his)unitary operation when encoding.They completed quantum dialogue successfully.Then the scheme′s security was discussed and a conclusion was drawn.Compared with the previous quantum dialogues,the secure quantum dialogue scheme adds the controlled party,ensures the communication security,and increases the particles number involving in the communication process and the coding efficiency.

ACTA PHOTONICA SINICA•Jan 1, 2013•1 citation

Quantum Communication Protocols Based on Hybrid Entanglement of Light

Giovanni Guccione, Adrien Cavaillès, Tom Darras +4 more

Hybrid entanglement of light combines two quantum information paradigms, the particle-like and the wave-like encodings, together. We report on recent experiments that engage this resource for two quantum communication protocols: remote state preparation and quantum steering.

Quantum Information and Measurement (QIM)•Jan 1, 2019•2 citations
We present results from an optical implementation of quantum orienteering, a protocol for communicating directions in space using quantum bits. We show how different types of measurements and encodings can be used to increase the communication efficiency. In particular, if Alice and Bob use two spin- particles for communication and employ joint measurements, they do better than is possible with local operations and classical communication. Furthermore, by using oppositely oriented spins, the achievable communication efficiency is further increased. Finally, we discuss the limitations of an optical approach: our results highlight the usually overlooked nonequivalence of different physical encodings of quantum bits.
Abstract This chapter discusses some of the ways in which quantum entanglement can be used for quantum communication. Suppose Alice and Bob share an entangled state: they can use it for dense coding, in which Alice sends Bob just one qubit of an entangled pair, which delivers two bits of classical information. Alice and Bob can also use an entangled state for teleportation, in which a qubit in a unknown quantum state is teleported from Alice to Bob when Alice sends Bob two classical bits. Entanglement swapping is an example of a tripartite communication protocol. If Alice and Bob share entanglement, and Bob and Charlie share entanglement, entanglement swapping can be used to entangle Alice and Charlie. Even if Alice and Bob are entangled, Alice cannot communicate with Bob without sending him classical bits or qubits, which prevents Alice and Bob from breaking the laws of relativity. This chapter also discusses Pauli matrices and the extension of Hilbert spaces.
This paper introduces a protocol for quantum communication that employs entangled and separable pairs of particles, enabling classical information transmission without the need for classical communication between the parties. In this system, one party, Alice, manipulates the entanglement degree of photon pairs within two distinct channels, |ψ⟩ 1 and |ψ⟩ 2. The other party, Bob, subsequently measures the state of these photons. This study uses the entanglement status of each photon pair to encode classical bits: entangled pairs |00⟩ + |11⟩ represent the bit '1', while separable pairs |00⟩ represent '0'. The proposed protocol incorporates a secondary quantum channel that enhances entanglement determination accuracy through additional measurements and phase shifts. The proposed approach stands apart from conventional quantum teleportation, which requires inter-party classical communication, by only requiring an internal classical link at the receiver's end for entanglement status resolution. The proposed method offers benefits when classical communication implementation is impractical or costly. The research highlights the potential of a fully quantum-based communication system, bridging the gap between quantum entanglement and quantum teleportation in a novel, pragmatic manner. While there is a need for improvements to enhance efficiency, security, and reliability, the proposed protocol offers a promising path for future explorations in quantum channel communication.
The natural choice of physical qubit for quantum communication is the photon: a photon can be transmitted quickly from the sender to a distant receiver and the technology for creating, manipulating, distributing, and measuring light pulses is well established. Many of these classical techniques can also be employed for quantum communication protocols. We will therefore focus our attention on optical setups for quantum communication. We will study a number of optical setups in the next few sections and use the conventions introduced in Chapter 4 to analyze them. In particular, we will assume that the qubits are encoded in the degrees of freedom of a single photon. Some of the main technical challenges in quantum communication arise from this need to work with single photon pulses. For instance, photons do not interact with each other in vacuum or linear media, and interactions between two photons in non-linear optical media are relatively small, so that realizing entangling two photon gates via coherent interactions is a challenging task. The quantum communication schemes discussed here circumvent this technical problem to a large extent. They only use non-linear optical materials for parametric down-conversion to create Bell-pairs of photons and then exploit standard linear optical devices and photo-detectors to manipulate them. No further non-linear entangling gates are required. Parametric down-conversion In non-linear optical media a single photon can be down-converted into a pair of photons. In this coherent process the incoming photon is destroyed and two photons of lower energy are created.
A scheme of quantum dialogue was proposed based on four-particle omega state.First,Bob,a communication party,prepared a four-particle omega state,encoded classical secret information by performing an approprite unitary transformation on two particles of the omega state and sent them to Alice.Then,Alice also performed an approprite unitary transformation on the two particles to encode secret information and sent back to Bob.Finally,Bob made joint measurement to final omega state,and announced the results.Alice and Bob,two parties of communication,could decode classical information the opposite one transfers,according to the announced measurement results and itself unitary operator,making the bidirectional communication come true.The result shows that the communication scheme only transfers two particles and makes unitary operations twice,and two communication parties get the opposite four-bit classcical information.It realizes both two-way communication of classical information with quantum channel and dense encoding to improve the communication capacity.The Eve′s intercept-resend attack can be found in time by inserting decoy photons in the system to raise the security of communication system.
A novel scheme of controlled secure quantum dialogue by using Brown states was proposed in this paper.It this scheme,Alice,Bob and Charlie shared a five-particle Brown states.Alice made unitary operations on two particles of the Brown states to realize encoding her secret calssical message.Similarly,Bob performed corresponding unitary transformations to another two particles to encode the information that he wanted to send to Alice.Later,Charlie made Brown base states joint measurement on the Brown final state and announced the measured results.Alice and Bob deduced the opposite party′s information according to Charlie′s announced measurement results and her(his)unitary operation when encoding.They completed quantum dialogue successfully.Then the scheme′s security was discussed and a conclusion was drawn.Compared with the previous quantum dialogues,the secure quantum dialogue scheme adds the controlled party,ensures the communication security,and increases the particles number involving in the communication process and the coding efficiency.