Free Republic

By shining a laser pulse sequence inspired by the Fibonacci numbers at atoms inside a quantum computer, physicists have created a remarkable, never-before-seen phase of matter. The phase has the benefits of two time dimensions despite there still being only one singular flow of time... This mind-bending property offers a sought-after benefit: Information stored in the phase is far more protected against errors than with alternative setups currently used in quantum computers. As a result, the information can exist without getting garbled for much longer, an important milestone for making quantum computing viable, says study lead author Philipp Dumitrescu. The...

Chinese scientists claim to have built the world’s fastest programmable quantum computers, which appear to crack problems that are currently not feasible for ”classical” non-quantum computers. The researchers led by Pan Jianwei from the University of Science and Technology of China (USTC), said one of the quantum computing systems — Zuchongzhi 2.1 — is a million times more powerful than its nearest competitor, Google’s Sycamore. Their programmable superconducting quantum computer, named after a 5th-century mathematician, is 10 million times faster than the world’s fastest supercomputer, the scientists said. Besides, their photonic quantum computer based on light — Jiuzhang 2 —...

A Microsoft-led team has withdrawn a controversial research paper into quantum computing, published in 2018. The research claimed to have found evidence of an elusive subatomic particle Microsoft suggested could help the development of more powerful computers. But it now says mistakes were made. The journal Nature has published a retraction. And the paper's authors have apologised for "insufficient scientific rigour". But the company has said it remains confident of its wider efforts on quantum computing. The paper had been hailed as a breakthrough. But some scientists remained sceptical. Quantum computing has been seen as a potentially revolutionary leap forward,...

IBM Q isn’t vaporware. It’s a project years-in-the-making that could help quantum computation reach its massive potential. The future of quantum computers may arrive sooner than you think. When news arrived of IBM’s move to offer the first commercially available universal quantum computer last week, it was characterized as a “handoff” from IBM Research to IBM Systems. According to the company’s CTO and vice president of quantum computing, technical strategy, and systems, Scott Crowder, that’s not entirely the case. “It’s not quite a ‘handoff,’ it’s really a partnership,” explained Crowder. “This is definitely a transition point from it being pure...

The actual problem that computer scientists threw at the D-Wave Two is pretty esoteric. To oversimplify it, they asked the machine to pick the optimum choice out of a large jumble of information with nearly 1,000 variables. Such optimization problems, which involve weighing multiple choices against each other, should be far, far easier for quantum computers to crunch. That's because the basis of quantum computation, the qubit, uses the odd physics of quantum mechanic to hold information as a zero, one, or a superposition of both. Again, to over-simplify things, this allows quantum computers to consider a vast number of...

Two years ago Google and NASA bought a D-Wave 2X quantum computing system and the Chocolate Factory has now pronounced itself very pleased with the results. "We found that for problem instances involving nearly 1000 binary variables, quantum annealing significantly outperforms its classical counterpart, simulated annealing. It is more than 108 times faster than simulated annealing running on a single core," Hartmut Neven, Google's director of engineering reported on Tuesday. Now comparing almost any operation against a single core is a bit of a fudge, but the results show that Google and NASA certainly feel D-Wave's take on quantum computing...

(Phys.org)—Due to quantum effects, it's possible to build a quantum computer that computes without running—or as the scientists explain, "the result of a computation may be learned without actually running the computer." So far, however, the efficiency of this process, which is called counterfactual computation (CFC), has had an upper limit of 50%, limiting its practical applications. Now in a new paper, scientists have experimentally demonstrated a slightly different version called a "generalized CFC" that has an efficiency of 85% with the potential to reach 100%. This improvement opens the doors to realizing a much greater variety of applications, such...

Ultracold beryllium ions tackle 160 randomly chosen programs Using a few ultracold ions, intense lasers and some electrodes, researchers have built the first programmable quantum computer. The new system, described in a paper to be published in Nature Physics, flexed its versatility by performing 160 randomly chosen processing routines. Earlier versions of quantum computers have been largely restricted to a narrow window of specific tasks. To be more generally useful, a quantum computer should be programmable, in the same way that a classical computer must be able to run many different programs on a single piece of machinery. The new...

In the past 5 years, no material has excited more interest from condensed matter physicists than graphene, a sheet of carbon only one atom thick. Electrons zing through the stuff in an unusual way, and they flow so easily that graphene could someday replace silicon and other semiconductors as the material of choice for microchips. Now, a team of physicists has taken a key step in fulfilling graphene's promise as a hotbed of exotic physics by showing that the electrons within it can team up to behave like particles with a fraction of the electron's charge. The effect is called...

Building upon recent studies on optomechanical entanglement with lasers and mirrors, a group of scientists has developed a theoretical model using entanglement swapping in order to entangle two micromechanical oscillators. This ability could lead to advances in information processing, as well as other applications that use micromechanical resonators, such as electrometers, displacement detectors, and radio frequency signal processors, wrote scientists Stefano Pirandola et al. in a recent Physical Review Letters. "Until now, entanglement has been observed only for optical modes, i.e., photons (which are massless particles)," Pirandola told PhysOrg.com. "The significance of purely mechanical entanglement would be that it involves...

from the April 22, 2004 edition - http://www.csmonitor.com/2004/0422/p14s01-stct.html Computermaker, embrace the weird!By Robert C. Cowen Interspecies entanglement. It might sound like a biological experiment gone wrong. Actually, it's a dream come true for physicists trying to invent an ultrafast computer. Welcome to the quaint world of quantum physics, whose weirdness frustrates theorists but whose promise could lead to a machine able to compute in seconds what would take today's supercomputers an eternity to complete. The key for researchers is to make use of that weirdness, starting with interspecies entanglement. In the language of quantum physics, different "species" means different...