scholarly journals A nondestructive Bell-state measurement on two distant atomic qubits

2021 ◽  
Author(s):  
Stephan Welte ◽  
Philip Thomas ◽  
Lukas Hartung ◽  
Severin Daiss ◽  
Stefan Langenfeld ◽  
...  
Keyword(s):  
Measurement Techniques ◽  
Bell State ◽  
Repeated Measurements ◽  
Entangled States ◽  
Entangled State ◽  
Initial State ◽  
Quantum Networks ◽  
Maximally Entangled State ◽  
Network Nodes ◽  
State Measurement

AbstractOne of the most fascinating aspects of quantum networks is their capability to distribute entanglement as a nonlocal communication resource1. In a first step, this requires network-ready devices that can generate and store entangled states2. Another crucial step, however, is to develop measurement techniques that allow for entanglement detection. Demonstrations for different platforms3–13 suffer from being not complete, destructive or local. Here, we demonstrate a complete and nondestructive measurement scheme14–16 that always projects any initial state of two spatially separated network nodes onto a maximally entangled state. Each node consists of an atom trapped inside an optical resonator from which two photons are successively reflected. Polarization measurements on the photons discriminate between the four maximally entangled states. Remarkably, such states are not destroyed by our measurement. In the future, our technique might serve to probe the decay of entanglement and to stabilize it against dephasing via repeated measurements17,18.

scholarly journals Connecting heterogeneous quantum networks by hybrid entanglement swapping

2020 ◽  
Vol 6 (22) ◽  
pp. eaba4508 ◽  
Author(s):  
Giovanni Guccione ◽  
Tom Darras ◽  
Hanna Le Jeannic ◽  
Varun B. Verma ◽  
Sae Woo Nam ◽  
...  
Keyword(s):  
Single Photon ◽  
Bell State ◽  
Entanglement Swapping ◽  
Entangled States ◽  
Heterogeneous Structure ◽  
Quantum Networks ◽  
Modular Systems ◽  
State Measurement ◽  
Future Networks ◽  
Different Types

Recent advances in quantum technologies are rapidly stimulating the building of quantum networks. With the parallel development of multiple physical platforms and different types of encodings, a challenge for present and future networks is to uphold a heterogeneous structure for full functionality and therefore support modular systems that are not necessarily compatible with one another. Central to this endeavor is the capability to distribute and interconnect optical entangled states relying on different discrete and continuous quantum variables. Here, we report an entanglement swapping protocol connecting such entangled states. We generate single-photon entanglement and hybrid entanglement between particle- and wave-like optical qubits and then demonstrate the heralded creation of hybrid entanglement at a distance by using a specific Bell-state measurement. This ability opens up the prospect of connecting heterogeneous nodes of a network, with the promise of increased integration and novel functionalities.

SCHEME FOR IMPLEMENTING ASSISTED CLONING OF AN UNKNOWN THREE-PARTICLE THREE-DIMENSION EQUATORIAL ENTANGLED STATE

2009 ◽  
Vol 07 (03) ◽  
pp. 653-660 ◽  
Author(s):  
PENG-CHENG MA ◽  
YOU-BANG ZHAN
Keyword(s):  
Bell State ◽  
The State ◽  
Entangled State ◽  
Three Dimension ◽  
Maximally Entangled State ◽  
Second Stage ◽  
Unknown State ◽  
State Measurement ◽  
Two Stages ◽  
State Case

In this paper, we proposed a protocol which can produce a perfect copy of an unknown three-particle three-dimension equatorial entangled state with assistance from a state preparer. Two stages were included in this protocol. The first stage requires usual teleportation, after Alice's (the state sender) generalized Bell-state measurement. Bob (the state receiver) can get the original state with a certain probability. In the second stage, after having received Victor's (the state preparer) classical message, and using the rest resource of the teleportation process, the perfect copy of an original unknown state can be produced in Alice's place. Furthermore, we have also investigated that the quantum channel is a non-maximally entangled state case. Alice also can re-establish the original unknown state in the certain probability.

QUANTUM AUTHENTICATION USING ENTANGLED STATES

2004 ◽  
Vol 15 (04) ◽  
pp. 609-617 ◽  
Author(s):  
XIAOYU LI ◽  
HOWARD BARNUM
Keyword(s):  
Bell State ◽  
Authentication Scheme ◽  
Entangled States ◽  
Bell State Measurement ◽  
Epr Pairs ◽  
State Measurement ◽  
Quantum Authentication ◽  
Einstein Podolsky Rosen

A quantum authentication scheme is presented in this paper. Two parties share Einstein-Podolsky-Rosen(EPR) pairs previously as the identification token. They create auxiliary EPR pairs to interact with the identification token. Then the authentication is accomplished by a complete Bell state measurement. This scheme is proved to be secure. If no errors and eavesdroppers exist in the transmission, the identification token is unchanged after the authentication. So it can be reused.

scholarly journals MAXIMALLY ENTANGLED STATES AND BELL'S INEQUALITY IN RELATIVISTIC REGIME

2009 ◽  
Vol 07 (01) ◽  
pp. 395-401 ◽  
Author(s):  
SHAHPOOR MORADI
Keyword(s):  
Ghz State ◽  
Entangled States ◽  
Entangled State ◽  
Maximally Entangled State ◽  
Expectation Value ◽  
Spin Observables ◽  
Chsh Inequality ◽  
Relativistic Regime ◽  
Maximal Violation ◽  
Maximally Entangled States

In this letter we show that in the relativistic regime, maximally entangled state of two spin-1/2 particles not only gives maximal violation of the Bell-CHSH inequality but also gives the largest violation attainable for any pairs of four spin observables that are noncommuting for both systems. Also, we extend our results to three spin-1/2 particles. We obtain the largest eigenvalue of Bell operator and show that this value is equal to the expectation value of Bell operator on GHZ state.

scholarly journals QUANTUM ENTANGLEMENT TRANSFER BETWEEN SPIN PAIRS

2010 ◽  
Vol 08 (07) ◽  
pp. 1111-1120 ◽  
Author(s):  
QING-YOU MENG ◽  
FU-LIN ZHANG ◽  
JING-LING CHEN
Keyword(s):  
Quantum Entanglement ◽  
Entangled State ◽  
Specific Time ◽  
Initial State ◽  
Maximally Entangled State ◽  
Initial States ◽  
Entanglement Transfer ◽  
Spin Pairs ◽  
Almost All

The transfer of entanglement from source particles (SPs) to target particles (TPs) via the Heisenberg interaction H = s1 ⋅ s2 has been investigated. In our research, TPs are two qubits and SPs are two qubits or qutrits. When TPs are two qubits, we find that no matter what state the TPs are initially prepared in, at the specific time t = π the quantity of entanglement of the TPs can attain 1 after interaction with the SPs which stay on the maximally entangled state. When TPs are two qutrits, the maximal quantity of entanglement of the TPs is proportional to the quantity of entanglement of the initial state of the TPs and cannot attain 1 for almost all the initial states of the TPs. Here we propose an iterated operation which can make the TPs go to the maximal entangled state.

Generalized three-party sharing of operations on remote single qutrit

2014 ◽  
Vol 12 (03) ◽  
pp. 1450011 ◽  
Author(s):  
Pengfei Xing ◽  
Yimin Liu ◽  
Chuanmei Xie ◽  
Xiansong Liu ◽  
Zhanjun Zhang
Keyword(s):  
Success Probability ◽  
Entangled States ◽  
Entangled State ◽  
Quantum Channels ◽  
Channel State ◽  
Classical Communication ◽  
Maximally Entangled State ◽  
Quantum Operations ◽  
Local Operation ◽  
Maximally Entangled States

Two three-party schemes are put forward for sharing quantum operations on a remote qutrit with local operation and classical communication as well as shared entanglements. The first scheme uses a two-qutrit and three-qutrit non-maximally entangled states as quantum channels, while the second replaces the three-qutrit non-maximally entangled state with a two-qutrit. Both schemes are treated and compared from the four aspects of quantum and classical resource consumption, necessary-operation complexity, success probability and efficiency. It is found that the latter is overall more optimal than the former as far as a restricted set of operations is concerned. In addition, comparisons of both schemes with other four relevant ones are also made to show their two features, including degree generalization and channel-state generalization. Furthermore, some concrete discussions on both schemes are made to expose their important features of security, symmetry and experimental feasibility. Particularly, it is revealed that the success probabilities and intrinsic efficiencies in both schemes are completely determined by the shared entanglement.

EFFICIENT SCHEME FOR TELEPORTATION OF UNKNOWN ATOMIC STATES USING NON-MAXIMALLY ENTANGLED STATES

2007 ◽  
Vol 21 (15) ◽  
pp. 923-927
Author(s):  
KUANG-WEI XIONG
Keyword(s):  
Cavity Qed ◽  
Bell State ◽  
Atomic State ◽  
Entangled States ◽  
Distinct Advantage ◽  
State Measurement ◽  
Cavity Decay ◽  
Efficient Scheme ◽  
Maximally Entangled States ◽  
Atomic States

We propose a feasible scheme for teleporting an unknown atomic state by using non-maximally entangled states in cavity QED. The distinct advantage of the scheme is that, not only can the teleportation and distillation procedure be realized simultaneously, but the scheme is also insensitive to the cavity decay and thermal field with the assistance of a strong classical driving field. In addition, the joint Bell-state measurement can be distinguished via detecting the atomic state.

Sign in / Sign up

Export Citation Format

Share Document