Using drones to create local quantum networks

Phys.org  January 18, 2021 Researchers in China built a small laser-generating device and affixed it to one of the drones. As it fired, photons were split in two, creating entangled pairs. One of the paired photons was directed toward another drone while the other was directed to a ground station. The drone that received the entangled photon served only as a relay—after refocusing, the photon was forwarded to a third drone, which then sent it to a second ground station. Motorized devices were used on the drones to ensure transmitters and received lined up properly for transmission of the entangled […]

When light and atoms share a common vibe

Phy.org  December 18, 2020 An international team of researchers (Switzerland, USA- MIT) entangled the photon and the phonon produced in the fission of an incoming laser photon inside the crystal by designing an experiment in which the photon-phonon pair could be created at two different instants. Classically, it would result in a situation where the pair is created at time t1 with 50% probability, or later t2 with 50% probability. They measured the decay of these hybrid photon-phonon Bell correlations with sub-picosecond time resolution and found that they survive over several hundred oscillations at ambient conditions. Their method offers a […]

Quantum entanglement realized between distant large objects

Phys.org  September 28, 2020 The disparity of hybrid systems and the vulnerability of quantum correlations have thus far hampered the generation of macroscopic hybrid entanglement. An international team of researchers (Spain, USA – University of Chicago, Denmark) generated an entangled state between the motion of a macroscopic mechanical oscillator and a collective atomic spin oscillator, as witnessed by an Einstein–Podolsky–Rosen variance below the separability limit, 0.83 ± 0.02 < 1. The mechanical oscillator is a millimetre-size dielectric membrane, and the spin oscillator is an ensemble of 109 atoms in a magnetic field. Light propagating through the two spatially separated systems […]

‘Hot and messy’ entanglement of 15 trillion atoms

Nanowerk  May 15, 2020 Quantum technologies often employ strong cooling and isolation to protect entangled entities from decoherence by random interactions. Researchers in Spain heated a collection of atoms to 450 Kelvin. The individual atoms collided with each other every few microseconds, and each collision set their electrons spinning in random directions. They observed an enormous number of entangled atoms – about 100 times more than ever before observed. The entanglement is non-local and the entanglement remains for about 1 millisecond, which means that 1000 times per second a new batch of 15 trillion atoms is being entangled. This clearly […]

Physicists develop new method to prove quantum entanglement

Phys.org  June 25, 2019 Building on a recent theoretical scheme, an international team of researchers (Austria, Serbia) successfully demonstrated that entanglement verification can be undertaken in a surprisingly efficient way and in a very short time, thus making this task applicable also to large-scale quantum systems. To test their new method, they experimentally produced a quantum system composed of six entangled photons. The results show that only a few experimental runs suffice to confirm the presence of entanglement with extremely high confidence, up to 99.99 percent. After a quantum system has been generated in the laboratory, the scientists carefully choose […]

Entangled Photons Sneak through Hole Unscathed

American Physical Society Focus  October 26, 2018 An international team of researchers (Austria, Australia, Spain, Italy) has demonstrated that quantum entanglement can be symmetry protected in the interaction with a single subwavelength plasmonic nanoaperture. By using specially engineered two-photon states to match the properties of the nanoaperture they demonstrated that two-photon entanglement can be either completely preserved or completely lost after the interaction with the nanoaperture, solely depending on the relative phase between the quantum states. The work should help in finding ways to keep delicate quantum information from being destroyed in future nanoscale chips… read more. TECHNICAL ARTICLE

Spatial overlap leads to useful quantum entanglement, say physicists

Physics World   June 25, 2018 Researchers in Italy studied independently prepared identical particles showing that, when they spatially overlap, an operational entanglement exists that can be made to manifest by means of separated localized measurements. They proved this entanglement is physical as it can be directly exploited to activate quantum information protocols, such as teleportation. These results establish that particle indistinguishability is a utilizable quantum feature and open the way to new quantum-enhanced applications… read more. TECHNICAL ARTICLE