A beautiful piece of engineering, not a quantum leap.
Category: quantum physics – Page 768
University of New South Wales researchers at the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) have shown for the first time that they can build atomic precision qubits in a 3D device — another major step towards a universal quantum computer.
The team of researchers, led by 2018 Australian of the Year and Director of CQC2T Professor Michelle Simmons, have demonstrated that they can extend their atomic qubit fabrication technique to multiple layers of a silicon crystal — achieving a critical component of the 3D chip architecture that they introduced to the world in 2015. This new research was published today in Nature Nanotechnology (“Spin read-out in atomic qubits in an all-epitaxial three-dimensional transistor”).
“Open Article” smile Spin-based quantum computers have the potential to tackle difficult mathematical problems that cannot be solved using ordinary computers, but many problems remain in making these machines scalable. Now, an international group of researchers led by the RIKEN Center for Emergent Matter Science have crafted a new architecture for quantum computing. By constructing a hybrid device made from two different types of qubit—the fundamental computing element of quantum computers –they have created a device that can be quickly initialized and read out, and that simultaneously maintains high control fidelity.
Single-spin qubits in semiconductor quantum dots hold promise for universal quantum computation with demonstrations of a high single-qubit gate fidelity above 99.9% and two-qubit gates in conjunction with a long coherence time. However, initialization and readout of a qubit is orders of magnitude slower than control, which is detrimental for implementing measurement-based protocols such as error-correcting codes. In contrast, a singlet-triplet qubit, encoded in a two-spin subspace, has the virtue of fast readout with high fidelity. Here, we present a hybrid system which benefits from the different advantages of these two distinct spin-qubit implementations. A quantum interface between the two codes is realized by electrically tunable inter-qubit exchange coupling. We demonstrate a controlled-phase gate that acts within 5.5 ns, much faster than the measured dephasing time of 211 ns. The presented hybrid architecture will be useful to settle remaining key problems with building scalable spin-based quantum computers.
Qubits Communications
Posted in computing, quantum physics
Qubits or quantum bits are the fundamental building block for quantum information processes. Whereas conventional computers store and process data as a series of ‘1’s and ‘0’s, quantum computers use the properties of a quantum system, such as the polarization of a photon or the spin of an electron.
Read the latest Research articles in Qubits from Nature Communications.
Hacker attacks on everything from social media accounts to government files could be largely prevented by the advent of quantum communication, which would use particles of light called “photons” to secure information rather than a crackable code.
Using light to send information is a game of probability: Transmitting one bit of information can take multiple attempts. The more photons a light source can generate per second, the faster the rate of successful information transmission.
“A source might generate a lot of photons per second, but only a few of them may actually be used to transmit information, which strongly limits the speed of quantum communication,” Bogdanov said.
For faster quantum communication, Purdue researchers modified the way in which a light pulse from a laser beam excites electrons in a man-made “defect,” or local disturbance in a crystal lattice, and then how this defect emits one photon at a time.
Researchers at the US Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) has developed and tested a new #Interferometer
January 3, 2019 — By analyzing a pattern formed by the intersection of two beams of light, researchers can capture elusive details regarding the behavior of mysterious phenomena such as gravitational waves. Creating and precisely measuring these interference patterns would not be possible without instruments called interferometers.
For over three decades, scientists have attempted to improve the sensitivity of interferometers to better detect how the number of photons—particles that make up visible light and other forms of electromagnetic energy—leads to changes in light phases. Attempts to achieve this goal are often hampered by optical loss and noise, both of which can decrease the accuracy of interferometer measurements.
But now a team of researchers at the US Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) has developed and tested a new interferometer to study the factors that contribute to these conditions, and they have devised solutions to overcome them. Their findings were published in the journal Applied Physics Letters, which promoted their paper to Editors’ Pick status. The editors award this distinction to noteworthy publications compiled in an exclusive list.
ARMONK, N.Y., Jan. 4, 2019 /PRNewswire/ — IBM (NYSE: IBM) Chairman, President and CEO Ginni Rometty will deliver the opening keynote at CES 2019 on Tuesday, Jan. 8. CES is the largest and one of the most influential technology events in the world.
Rometty will show how technologies like artificial intelligence, blockchain and cloud are reshaping the world of business, and, in turn, our daily lives. She also will talk about what’s coming next in these pioneering technologies – and how new data will revolutionize how we live, work and play. Rometty shares perspective on the future of technology in the Consumer Technology Association magazine It Is Innovation (i3) CES edition: https://www.nxtbook.com/nxtbooks/manifest/i3_20190102
Rometty will be joined onstage by Ed Bastian, CEO of Delta Air Lines; Charles Redfield, executive vice president of Food for Walmart; and Vijay Swarup, vice president of R&D for ExxonMobil.