Quantum entanglement—or what Albert Einstein once referred to as “spooky action at a distance”— occurs when two quantum particles are connected to each other, even when millions of miles apart. Any observation of one particle affects the other as if they were communicating with each other. When this entanglement involves photons, interesting possibilities emerge, including entangling the photons’ frequencies, the bandwidth of which can be controlled.
‘Optical Accelerators’ ditch electricity, favoring light as an exchange medium.
Researchers with IBM and Moscow’s Skolkovo Institute have developed “optical accelerators” — optical switches that use light instead of electricity to convey state changes and transmit information. The inventors claim an up to 1,000x speedup compared to traditional transistor-based switches — and there are applications for both classical and quantum computing.
Quantum physicists at the University of Copenhagen are reporting an international achievement for Denmark in the field of quantum technology. By simultaneously operating multiple spin qubits on the same quantum chip, they surmounted a key obstacle on the road to the supercomputer of the future. The result bodes well for the use of semiconductor materials as a platform for solid-state quantum computers.
One of the engineering headaches in the global marathon towards a large functional quantum computer is the control of many basic memory devices—qubits—simultaneously. This is because the control of one qubit is typically negatively affected by simultaneous control pulses applied to another qubit. Now, a pair of young quantum physicists at the University of Copenhagen’s Niels Bohr Institute working in the group of Assoc. Prof. Ferdinand Kuemmeth, have managed to overcome this obstacle.
Global qubit research is based on various technologies. While Google and IBM have come far with quantum processors based on superconductor technology, the UCPH research group is betting on semiconductor qubits—known as spin qubits.
Physicists and engineers have long been interested in creating new forms of matter, those not typically found in nature. Such materials might find use someday in, for example, novel computer chips. Beyond applications, they also reveal elusive insights about the fundamental workings of the universe. Recent work at MIT both created and characterized new quantum systems demonstrating dynamical symmetry—particular kinds of behavior that repeat periodically, like a shape folded and reflected through time.
“There are two problems we needed to solve,” says Changhao Li, a graduate student in the lab of Paola Cappellaro, a professor of nuclear science and engineering. Li published the work recently in Physical Review Letters, together with Cappellaro and fellow graduate student Guoqing Wang. “The first problem was that we needed to engineer such a system. And second, how do we characterize it? How do we observe this symmetry?”
Concretely, the quantum system consisted of a diamond crystal about a millimeter across. The crystal contains many imperfections caused by a nitrogen atom next to a gap in the lattice—a so-called nitrogen-vacancy center. Just like an electron, each center has a quantum property called a spin, with two discrete energy levels. Because the system is a quantum system, the spins can be found not only in one of the levels, but also in a combination of both energy levels, like Schrodinger’s theoretical cat, which can be both alive and dead at the same time.
And they say it’s the world’s fastest.
It appears a quantum computer rivalry is growing between the U.S. and China.
Physicists in China claim they’ve constructed two quantum computers with performance speeds that outrival competitors in the U.S., debuting a superconducting machine, in addition to an even speedier one that uses light photons to obtain unprecedented results, according to a recent study published in the peer-reviewed journals Physical Review Letters and Scienc… See More.
Laura Hiscott reviews Quantum Technology | Our Sustainable Future by The Quantum Daily.
How could quantum computing help us to fix climate change? This is the question at the heart of Quantum Technology | Our Sustainable Future, a half-hour-long documentary published on YouTube in July.
Made by “The Quantum Daily”, a resource for news and information on all things quantum, the documentary consists of interviews with people working in a host of organizations in the sector, from Oxford Instruments NanoScience to Google Quantum AI. The main idea is that, since quantum computers have the potential to be much more powerful than classical ones, they could speed up the discovery of solutions, such as molecules that would be very effective at carbon capture.
The infamous twin paradox sends the astronaut Alice on a blazing-fast space voyage. When she returns to reunite with her twin, Bob, she finds that he has aged much faster than she has. It’s a well-known but perplexing result: Time slows if you’re moving fast.
Gravity does the same thing. Earth — or any massive body — warps space-time in a way that slows time, according to Albert Einstein’s general theory of relativity. If Alice lived her life at sea level and Bob at the top of Everest, where Earth’s gravitational pull is slightly weaker, he would again age faster. The difference on Earth is modest but real — it’s been measured by putting atomic clocks on mountaintops and valley floors and measuring the difference between the two.
Physicists have now managed to measure this difference to the millimeter. In a paper posted earlier this month to the scientific preprint server arxiv.org, researchers from the lab of Jun Ye, a physicist at JILA in Boulder, Colorado, measured the difference in the flow of time between the top and the bottom of a millimeter-tall cloud of atoms.
Don’t let the titanium metal walls or the sapphire windows fool you. It’s what’s on the inside of this small, curious device that could someday kick off a new era of navigation.
For over a year, the avocado-sized vacuum chamber has contained a cloud of atoms at the right conditions for precise navigational measurements. It is the first device that is small, energy-efficient and reliable enough to potentially move quantum sensors—sensors that use quantum mechanics to outperform conventional technologies—from the lab into commercial use, said Sandia National Laboratories scientist Peter Schwindt.
Sandia developed the chamber as a core technology for future navigation systems that don’t rely on GPS satellites, he said. It was described earlier this year in the journal AVS Quantum Science.
