Phys.org September 23, 2019 Past research has shown that applying a magnetic field can shift the energy of the valleys in opposite directions, lowering the energy of one valley to make it “deeper” and more attractive to electrons, while raising the energy of the other valley to make it “shallower,” A team of researchers in the US (SUNY Buffalo, University of Nebraska) showed that the shift in the energy of the two valleys can be enlarged by two orders of magnitude if we place a thin layer of magnetic europium sulfide under the tungsten disulfide. After that when they applied […]
Tag Archives: Quantum computing
Physicists ‘teleport’ logic operation between separated ions
Science Daily May 30, 2019 Teleportation of quantum data has been demonstrated previously with ions and a variety of other quantum systems. Now a team of researchers in the US (NIST, University of Colorado) teleported a quantum controlled-NOT (CNOT) logic operation, or logic gate, between two beryllium ion qubits located more than 340 micrometers apart in separate zones of an ion trap, a distance that rules out any substantial direct interaction. A “messenger” pair of entangled magnesium ions is used to transfer information between the beryllium ions (infographic ). They found that its teleported CNOT process entangled the two magnesium ions […]
An Optimist’s View of the 4 Challenges to Quantum Computing
IEEE Spectrum March 22, 2019 According to some experts quantum computing will never materialize as it will require control over an exponentially large number of quantum states, and that this amount of control is too difficult to achieve. According to Intel there are four key challenges that could keep quantum computing from becoming a reality – Qubit Quality, Error Correction, Qubit Control, Too Many Wires. Researches at Intel are working to tackle each of these challenges. But if solved, we could create a commercially relevant quantum computer in about 10-12 years… read more.
Quantum strangeness gives rise to new electronics
Eurekalert February 11, 2019 An international team of researchers (USA – Arizona State University, Japan, China, UK) explored the charge transport properties through the molecules. They demonstrated that quantum interference can be precisely modulated in two different configurations of the molecule, known as Para and Meta. It turns out that quantum interference effects can cause substantial variation in the conductance properties of molecule-scale devices. By controlling the quantum interference, the group showed that electrical conductance of a single molecule can be fine-tuned over two orders of magnitude. The research shows that the field of molecular electronics is open to a […]
Scientists design new material to harness power of light
Phys.org December 17, 2018 An international team of researchers (USA – MIT, University of Hartford, UK. France) found that several materials with poor nonlinear characteristics can be combined, resulting in a new metamaterial that can be “tuned” to change the color of light. The enhancement comes from the way the metamaterial reshapes the flow of photons. They describe the underlying physics, compare its predictions to the experimental results, and analyze the limits of its applicability. The work opens a new direction in controlling the nonlinear response of materials and may find applications in on-chip optical circuits, drastically improving on-chip communications…read […]
Imperfections make photons perfect for quantum computing
Nanowerk December 17, 2018 Researchers at Rice University found that in molybdenum disulfide a dash of rhenium in just the right spot makes a configuration of atoms with energy states that sit comfortably inside and are isolated from the material’s natural band gap. Aligning magnetic moments of atoms in the defect and exciting them with light brings them to a higher energetic state making them exit as single photon. The direction of the photon is not understood, but the researchers suspect that it is well defined. The defect’s optical transition lies in the optical fiber telecommunication band, which is ideal […]
Senate bill would direct DOD to create a quantum computing consortium
Fed Scoop June 8, 2018 The consortium would be a partnership of various defense, federal, industry and academic research entities selected by the chief of the Office of Naval Research in the eastern half of the nation and the director of the Army Research Laboratory in the western half. Those two would oversee the consortium with the assistant director for quantum information science at the White House Office of Science and Technology Policy and other experts. The board would award grants, facilitate partnerships and assist in quantum information science research within the group… read more.
Light could make semiconductor computers a million times faster or even go quantum
Phys.org May 10, 2018 An international team of researchers (Germany, USA – University of Michigan) has demonstrated that a single layer of tungsten and selenium in a honeycomb lattice produces a pair of electron states known as pseudospins that can encode the 1 and 0. They prodded electrons into these states with quick pulses of infrared light. The initial pulse has its own spin, known as circular polarization, that sends electrons into one pseudospin state. Pulses of light that don’t have a spin can push the electrons from one pseudospin to the other—and back again. The work opens the door […]
Scaling silicon quantum photonic technology
Physorg March 9, 2018 An international team of researchers (UK, China, Denmark, Germany, Poland, Spain) has demonstrated a programmable path-encoded multidimensional entangled system with dimension up to 15×15, where two photons exist over 15 optical paths at the same time and are entangled with each other. This multidimensional entanglement is realised by exploiting silicon-photonics quantum circuits, integrating in a single chip, 550 optical components, including 16 identical photon-pair sources, 93 optical phase-shifters, 122 beam-splitters. The research provides a clear path to scaling up to the many millions of components that are ultimately needed for large-scale quantum computing applications… read more. […]
Approximate quantum cloning: The new way of eavesdropping in quantum cryptography
Physorg February 20, 2018 Uncertainty at the quantum scale makes exact cloning of quantum states impossible. Yet, they may be copied in an approximate way using probabilistic quantum cloning. Continuing previous work, researchers in China showed that if an independent subset cannot be expressed as the superposition of the other states in the set, then these dependent states can be partially cloned. Cloning operation allows scientists to make many copies of the output of computations—which take the form of unitary operations. These can, in turn, be used as input and fed into various further processes. Cloning also has applications in […]