Particles with unusual properties called anyons have long been sought after as a potential building block for advanced quantum computers, and now researchers have found one – using a quantum computer.
By Alex Wilkins
Category: computing – Page 343
Researchers demonstrate electrical creation and control of antiferromagnetic vortices
A new study has shown for the first time how electrical creation and control of magnetic vortices in an antiferromagnet can be achieved, a discovery that will increase the data storage capacity and speed of next generation devices.
Researchers from the University of Nottingham’s School of Physics and Astronomy have used magnetic imaging techniques to map the structure of newly formed magnetic vortices and demonstrate their back-and-forth movement due to alternating electrical pulses. Their findings have been published in Nature Nanotechnology.
“This is an exciting moment for us, these magnetic vortices have been proposed as information carriers in next-generation memory devices, but evidence of their existence in antiferromagnets has so far been scarce. Now, we have not only generated them, but also moved them in a controllable way. It’s another success for our material, CuMnAs, which has been at the center of several breakthroughs in antiferromagnetic spintronics over the last few years,” says Oliver Amin.
Quantum Computing Algorithm Breakthrough Brings Practical Use Closer to Reality
Out of all common refrains in the world of computing, the phrase “if only software would catch up with hardware” would probably rank pretty high. And yet, software does sometimes catch up with hardware. In fact, it seems that this time, software can go as far as unlocking quantum computations for classical computers. That’s according to researchers with the RIKEN Center for Quantum Computing, Japan, who have published work on an algorithm that significantly accelerates a specific quantum computing workload. More significantly, the workload itself — called time evolution operators — has applications in condensed matter physics and quantum chemistry, two fields that can unlock new worlds within our own.
Normally, an improved algorithm wouldn’t be completely out of the ordinary; updates are everywhere, after all. Every app update, software update, or firmware upgrade is essentially bringing revised code that either solves problems or improves performance (hopefully). And improved algorithms are nice, as anyone with a graphics card from either AMD or NVIDIA can attest. But let’s face it: We’re used to being disappointed with performance updates.
New Quantum Computer Algorithm Unlocks the Power of Atomic-Level Interactions
A novel protocol for quantum computers could reproduce the complex dynamics of quantum materials.
RIKEN researchers have created a hybrid quantum-computational algorithm that can efficiently calculate atomic-level interactions in complex materials. This innovation enables the use of smaller quantum computers or conventional ones to study condensed-matter physics and quantum chemistry, paving the way for new discoveries in these fields.
A quantum-computational algorithm that could be used to efficiently and accurately calculate atomic-level interactions in complex materials has been developed by RIKEN researchers. It has the potential to bring an unprecedented level of understanding to condensed-matter physics and quantum chemistry—an application of quantum computers first proposed by the brilliant physicist Richard Feynman in 1981.
Quantum Computers Could Be a ‘Superhighway’ to Experiencing Our Other Selves in the Multiverse
It could be a strange way of achieving immortality—or at least, everlasting life for copies of you.
Quantum Spin Hall Effect Seen in Graphene Analog
Graphene’s valence and conduction bands meet at a point, making the single-layer crystal a semimetal. Researchers have predicted that spin-orbit coupling of carbon’s outer electrons opens a narrow gap between these bands—but only for the crystal’s bulk. Along the edges, spin-dependent states bridge the band gap, allowing the resistance-free flow of electrons: a quantum spin Hall effect. The weakness of carbon’s spin-orbit coupling means that this quantum spin Hall effect is too fragile to observe, however. Now Pantelis Bampoulis of the University of Twente in the Netherlands and his collaborators have seen the quantum spin Hall effect in graphene’s germanium (Ge) analog, germanene [1]. Furthermore, they show that germanene’s structure—a honeycomb like graphene’s, but lightly buckled—allows the quantum spin Hall effect to be turned off and on using an electric field.
Bampoulis and his collaborators grew a germanene monolayer on a buffer layer of Ge atop a substrate of Ge2Pt. Using a scanning tunneling microscope, they discriminated between the edge and the bulk states of germanene and measured how current depended on voltage under an external electric field perpendicular to the layer. At low field strengths, germanene exhibited a robust quantum spin Hall effect due to germanium’s strong spin-orbit coupling. At high field strengths, the edge states no longer bridged the gap and germanene became a normal insulator. But at a critical intermediate value, germanene underwent a topological phase transition as the otherwise separated conduction and valence bands in the bulk came together and the symmetry that sustained the quantum spin Hall effect was destroyed.
The robustness of germanene’s quantum spin Hall effect and the fact that it can be turned off with an applied electric field suggest that the material could be used to make room-temperature topological field-effect transistors.