Science Daily February 25, 2019 A team of researchers in the US (NIST, University of Maryland) created quantum-correlated pairs made up of one visible and one near-infrared photon. The visible-light partners can interact with trapped atoms, ions, or other systems that serve as quantum versions of computer memory while the near-infrared members of each couple are free to propagate over long distances through the optical fiber. The design methods can be easily applied to create many other visible-light/near-infrared pairs tailored to match specific systems of interest. In the future, by combining two of the entangled pairs with two quantum memories, […]
Tag Archives: Quantum entanglement
New study could hold key to hack-proof systems
Phys.org July 17, 2018 An international team of researchers (Austria, France, Czech Republic, Slovakia, Switzerland, Spain, UK) show how carefully constructed measurements in two bases (one of which is not orthonormal) can be used to faithfully and efficiently certify bipartite high-dimensional states and their entanglement for any physical platform. In an experimental set-up, they were able to verify 9-dimensional entanglement for a pair of photons on a 11-dimensional subspace each. The group is currently looking into a more direct use of this technique in actual quantum cryptography protocols and expect their technique to be widely applied in other quantum systems […]
How can you tell if a quantum memory is really quantum?
Phys.org May 23, 2018 Often it is difficult to tell whether a memory is storing quantum or merely classical information. The new test developed by an international team of researchers (Taiwan, Switzerland, Japan, Canada) uses a semiquantum framework that is very similar to that used in some tests of entanglement. By comparing the relative frequencies of the sent and received signals it is possible to estimate the time-like entanglement and therefore certify that a quantum memory can store quantum information. They showed that the new test is robust against noise and losses, and they expect that it should be possible […]