Qubits as valves: Controlling quantum heat engines

Science Daily  July 9, 2018 Researchers in Finland assembled a miniature heat valve in a quantum system composed of a superconducting qubit to study heat transport. Using a qubit controlled by a magnetic field as a “valve,” they could either block or release the flow of photons carrying the heat through the qubit between two “heat baths” formed of metallic resistors. They aim to understand, combining experimental and theoretical efforts, how quantum refrigerators and heat engines work. This effort would ultimately bridge the gap between the fields of quantum information and thermodynamics of mesoscopic systems… read more. TECHNICAL ARTICLE

Scientists teach the neural network to carry out video facial recognition — using a single photo

Eurekalert  July 5, 2018 Researchers in Russia used the theory of fuzzy sets and probability theory to develop a video recognition algorithm. The algorithm significantly improves the accuracy (by 2-6% compared to earlier experiments) of identifying faces by video in real time with a small number of images for several well-known neural network architectures, such as VGGFace, VGGFace2, ResFace and LightCNN. It estimates to what degree one frame is closer to one person, and to what degree the other frame is closer to the next person. Then it compares how similar the training still photos of these two people are […]

A step closer to single-atom data storage

Phys.org  July 10, 2018 Researchers in France found that the holmium atoms could retain record-breaking coercivity in a magnetic field exceeding 8 Tesla. Only at around 45K, the magnets began to spontaneously align themselves to the applied magnetic field. This showed that they can withstand relatively high temperature perturbations and might point to the way forward for running single-atom magnets at more commercially viable temperatures. Each atom can store a single bit of data that can be written and read using quantum mechanics. Such devices promise enormous data capacities… read more. Open Access TECHNICAL ARTICLE

A Step Toward Quantum Repeaters

Optics and Photonics  July 6, 2018 An international team of researchers (USA – Princeton University, Gemological Institute of America, UK) reports a color center that shows insensitivity to environmental decoherence caused by phonons and electric field noise: the neutral charge state of silicon vacancy (SiV0). Through careful materials engineering, they achieved >80% conversion of implanted silicon to SiV0. SiV0 exhibits spin-lattice relaxation times approaching 1 minute and coherence times approaching 1 second. Its optical properties are very favorable, with ~90% of its emission into the zero-phonon line and near–transform-limited optical linewidths. These combined properties make SiV0 a promising defect for […]

Trapping light using Tetris-like clusters of crystals

Nanowerk  July 10, 2018 Lack of precision and control often produced photonic crystals that have inconsistent defects that jeopardise their commercial performance. Working under a project funded by the EU Future and Emerging Technologies (FET) programme, an international team of researchers (France, Sweden, Israel) has developed a new microfluidic set-up, where researchers can ‘bend matter’, enabling them to re-organise the colloidal droplet clusters used to fabricate the crystals into Tetris-like blocks. The clusters have sizes ranging between two to five monodispersed droplets with an average size of 400nm and are highly replicable. Using this technique allows researchers to easily construct […]

Top 10 Science and Technology Innovations for the Week of July 6, 2018

01. Spectral cloaking could make objects invisible under realistic conditions 02. Controlling photons with a photon 03. Quantum-enhanced sensing of magnetic fields 04. New photodetector could improve night vision, thermal sensing and medical imaging 05. Rotating resonator creates a one-way street for light 06. Sandia light mixer generates 11 colors simultaneously 07. Magnetic skyrmions: Not the only ones of their class 08. Game changing invention to revolutionise cybersecurity 09. New coatings make natural fabrics waterproof 10. ‘Breakthrough’ algorithm exponentially faster than any previous one And others… Computational intelligence-inspired clustering in multi-access vehicular networks The culprit of some GaN defects could […]

Controlling photons with a photon

Phys.org June 28, 2018 To realize the strong light-matter interaction that is necessary for all-optical quantum devices, a team of researchers in the US (Harvard University, MIT) used a laser-cooled ensemble of 87Rb atoms (~10 uK) trapped within a high-finesse optical resonator (finesse ~50000) in an ultrahigh-vacuum chamber. To switch a photon with a photon in such a system, they used ‘vacuum-induced transparency’ in which an electromagnetic field as weak as a vacuum field is shown to alter the optical properties of atoms. The research is a step towards deterministic multi-mode entanglement generation as well as high-fidelity photonic quantum gates […]

The culprit of some GaN defects could be nitrogen

Nanowerk June 29, 2018 Gallium nitride’s defects and degradation are due to the atoms being displaced in the crystal lattice structure. An international team of researchers (Greece, Algeria, France) used computational analysis to determine the structural and electronic properties of a-type basal edge dislocations along the <1-100> direction in GaN which are common in semipolar growth orientations. They studied three models with different core configurations – three nitrogen atoms and one gallium atom for the Ga polarity; four N atoms and two Ga atoms; two N atoms and two Ga core-associated atoms. They found a connection between the smaller bandgap […]

The Future of Cybersecurity Is the Quantum Random Number Generator

IEEE Spectrum June 28, 2018 Nearly 140 years back Frank Miller proposed encrypting messages by shifting each letter in the message by a random number of places, resulting in a string of gibberish. And ever since, cryptographers have tried to devise a way to generate and distribute the unique and truly random numbers that the technique requires. This article reviews the various developments in random number generating research. Researchers have made good progress in recent years in developing technologies that can generate and distribute truly random numbers. By measuring the unpredictable attributes of subatomic particles, these devices can use the […]

Game changing invention to revolutionise cybersecurity

Phys.org  July 2, 2018 Researchers in the UK propose using resonant tunnelling diodes as practical true random number generators based on a quantum mechanical effect. The output of the proposed devices can be directly used as a random stream of bits or can be further distilled using randomness extraction algorithms, depending on the application. With the lowest power requirements and high scalability due to the simple semiconductor structure it is hoped that this innovation will play a pivotal role in protecting both consumers and businesses across the globe in their digital futures… read more. Open Access TECHNICAL ARTICLE