Most quantum system with short-ranged interactions show a fast decay of entanglement with the distance. In this Letter, we focus on the peculiarity of some systems to distribute entanglement between distant parties. Even in realistic models, like the spin-1 Heisenberg chain, sizable entanglement is present between arbitrarily distant particles. We show that long-distance entanglement appears for values of the microscopic parameters which do not coincide with known quantum critical points, hence signaling a transition detected only by genuine quantum correlations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.96.247206 | DOI Listing |
We propose a scheme to generate nonreciprocal entanglement and one-way steering between two distant ferrimagnetic microspheres in waveguide electromagnonics, where the magnon modes of two yttrium iron garnet (YIG) spheres are simultaneously coupled to each other through coherent and dissipative interactions. By matching the coherent interaction with its corresponding dissipative counterpart, unidirectional coupling between two magnon modes can be realized, and then in the presence of significant Kerr nonlinearities, we can obtain strong entanglement and one-way steering. Depending on the direction of the microwave propagation, the long-distance entanglement and steering can be generated nonreciprocally.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Rep Prog Phys
November 2024
National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstrucstures, Nanjing University, Nanjing 210093, People's Republic of China.
A full-fledged quantum network relies on the formation of entangled links between remote location with the help of quantum repeaters. The famous Duan-Lukin-Cirac-Zoller quantum repeater protocol is based on long distance single-photon interference (SPI), which not only requires high phase stability but also cannot generate maximally entangled state. Here, we propose a quantum repeater protocol using the idea of post-matching, which retains the same efficiency as the SPI protocol, reduces the phase-stability requirement and can generate maximally entangled state in principle.
View Article and Find Full Text PDFNat Commun
November 2024
Toshiba Europe Limited, 208 Science Park, Milton Road, Cambridge, CB4 0GZ, UK.
Quantum networks, relying on the distribution of quantum entanglement between remote locations, have the potential to transform quantum computation and secure long-distance quantum communication. However, a fundamental ingredient for fibre-based implementations of such networks, namely entanglement between a single spin and a photon directly emitted at telecom wavelengths, has been unattainable so far. Here, we use a negatively charged exciton in an InAs/InP quantum dot to implement an optically active spin qubit taking advantage of the lowest-loss transmission window, the telecom C-band.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!