Nanowerk December 30, 2019 An international team of researchers ( USA- University of Chicago, UC Santa Barbara, Argonne National Laboratory, Japan) created a hybrid quantum system that acoustically drives transitions in electron spins. The experiment showed a basis for mechanical (strain) control. They developed a theoretical model from a combination of direct experimental observation and density functional theory calculations. From all of this information, they illustrated different types of mechanical strain that drive longer-lasting spins. The material studied was silicon carbide, which has been shown recently to support long-lived spin states that can be accessed optically. The results offer theoretical […]
Tag Archives: Quantum communication
China’s Quantum Satellite Security Has Been Broken
Next Big Future August 22, 2019 Although quantum key distribution (QKD) security can theoretically be unbreakable, the actual implementations are not perfect and have been broken. In a spree of publications thereafter, an international team of researchers (Norway, Germany) has now demonstrated several methods to successfully eavesdrop on commercial QKD systems based on weaknesses of avalanche photodiodes operating in gated mode. This has sparked research on new approaches to securing communications networks…read more. Open Access TECHNICAL ARTICLE
World’s first link layer protocol brings quantum internet closer to a reality
Phys.org August 20, 2019 Researchers in the Netherlands have developed a link layer protocol they identified for use in fundamental and technological design considerations of quantum network hardware. They illustrated it by considering the state-of-the-art quantum processor platform, Nitrogen-Vacancy (NV) centers in diamond. They examined the robustness and performance of the protocol. They implemented the protocol and successfully validated the physical simulation model against data gathered from the NV hardware. The protocol is robust. They studied the performance of the protocols for 169 distinct simulation scenarios and initiated the study of quantum network scheduling strategies to optimize protocol performance for […]
‘Connecting the dots’ for quantum networks
Science Daily July 9, 2019 For quantum dots to “communicate”, they must emit light at the same wavelength. The size of a quantum dot determines this emission wavelength. Instead of making quantum dots perfectly identical to begin with, researchers at the US Naval Research Laboratory change their wavelength afterwards by shrink-wrapping them with laser-crystallized hafnium oxide, squeezing the quantum dots, which shifts their wavelength in a very controllable way. Doing this for many quantum dots in an integrated circuit, could be used for optical, rather than electrical computing. The technique could accelerate the development of quantum information technologies and brain-inspired […]
Researchers teleport information within a diamond
EurekAlert June 28, 2019 Researchers in Japan have demonstrated quantum state transfer of photon polarization into a carbon isotope nuclear spin coupled to a nitrogen-vacancy center in diamond based on photon-electron Bell state measurement by photon absorption. The carbon spin is first entangled with the electron spin, which is then permitted to absorb a photon into a spin-orbit correlated eigenstate. Detection of the electron after relaxation into the spin ground state allows post-selected transfer of arbitrary photon polarization into the carbon memory. The study has big implications for quantum information technology…read more. Open Access TECHNICAL ARTICLE
An important step towards completely secure quantum communication network
Phys.org November 28, 2018 For practical long-distance quantum communication room-temperature atomic vapours are important. Atomic motion has so far limited the single-excitation lifetime in such systems to the microsecond range. Researchers in Denmark have demonstrated that lifespan of the quantum state at room temperature can be extended to about a quarter of a millisecond. They used a small glass container, filled with Cesium atoms, in which they were able to load, store and retrieve single photons from, the quantum states necessary for the repeater. This technique improves the life span of the quantum states at room temperature a hundred times…read […]
QuTech researchers put forward a roadmap for quantum internet development
Delft University of Technology (the Netherlands) October 18, 2018 Researchers in the Netherlands describe six phases, starting with simple networks of qubits that could already enable secure quantum communications – a phase that could be reality in the near future. The development ends with networks of fully quantum-connected quantum computers. In each phase, new applications become available such as extremely accurate clock synchronization or integrating different telescopes on Earth in one virtual ‘supertelescope’. This work creates a common language that unites the highly interdisciplinary field of quantum networking towards achieving the dream of a world-wide quantum internet… read more. TECHNICAL […]
Scientists gain new visibility into quantum information transfer
MIT News March 8, 2018 A team of researchers in the US (MIT, Dartmouth College) combined NMR techniques with their knowledge of the spin dynamics in their crystal, whose geometry approximately confines the evolution to linear spin chains. It allowed them to figure out a metric, average correlation length, for how many spins are connected to each other in a chain and determine if the interaction is winning or disorder is winning keeping the system in a more quantum localized state. The method represents a possible advance toward the ability to control localization. Because many-body localization preserves information and prevents […]
‘Two-way signaling’ possible with a single quantum particle
Physorg February 26, 2018 By using a quantum particle that has been put in a superposition of two different locations, researchers in Austria have theoretically shown that both partners are able to encode their messages into a single quantum particle simultaneously. Being in a quantum superposition means that the quantum particle is “simultaneously present” at each partner’s location. Therefore, both partners are able to encode their messages into a single quantum particle simultaneously, a task that is essentially impossible using classical physics. The experimental results show that the communication is secure and anonymous, the direction of communication is hidden—an eavesdropper […]
Developing a secure, un-hackable net
Physorg January 11, 2018 A method of securely communicating between multiple quantum devices developed by researchers in the UK does not rely on assumptions, but instead it uses the quantum laws of physics to ensure security, which would need to be broken to hack the encryption. They report on a way of communicating securely between three or more quantum devices, irrespective of who built them. The method works by using the network’s structure to limit what an eavesdropper can learn. They used machine learning and causal inference to develop the test for the un-hackable communications system. This approach distributes secret […]