Lifeboat Foundation

For two decades, physicists have tried to directly manipulate the spin of electrons in 2D materials like graphene. Doing so could spark key advances in the burgeoning world of 2D electronics, a field where super-fast, small and flexible electronic devices carry out computations based on quantum mechanics.

Standing in the way is that the typical way in which scientists measure the spin of electrons—an essential behavior that gives everything in the physical universe its structure—usually doesn’t work in 2D materials. This makes it incredibly difficult to fully understand the materials and propel forward technological advances based on them. But a team of scientists led by Brown University researchers believe they now have a way around this longstanding challenge. They describe their solution in a new study published in Nature Physics.

In the study, the team—which also include scientists from the Center for Integrated Nanotechnologies at Sandia National Laboratories, and the University of Innsbruck—describe what they believe to be the first measurement showing direct interaction between electrons spinning in a 2D material and photons coming from microwave radiation.

A new experiment uses superconducting qubits to demonstrate that quantum mechanics violates what’s called local realism by allowing two objects to behave as a single quantum system no matter how large the separation between them. The experiment wasn’t the first to show that local realism isn’t how the Universe works—it’s not even the first to do so with qubits.

But it’s the first to separate the qubits by enough distance to ensure that light isn’t fast enough to travel between them while measurements are made. And it did so by cooling a 30-meter-long aluminum wire to just a few milliKelvin. Because the qubits are so easy to control, the experiment provides a new precision to these sorts of measurements. And the hardware setup may be essential for future quantum computing efforts.

The silicon microchips of future quantum computers will be packed with millions, if not billions of qubits—the basic units of quantum information—to solve the greatest problems facing humanity. And with millions of qubits needing millions of wires in the microchip circuitry, it was always going to get cramped in there.

But now engineers at UNSW Sydney have made an important step toward solving a long-standing problem about giving their qubits more breathing space—and it all revolves around jellybeans.

Continue reading “Jellybeans: A sweet solution for overcrowded circuitry in quantum computer chips” »

In the United States, the first step on the road to exascale HPC systems began with a series of workshops in 2007. It wasn’t until a decade and a half later that the 1,686 petaflops “Frontier” system at Oak Ridge National Laboratory went online. This year, Argonne National Laboratory is preparing for the switch to be turned on for “Aurora,” which will be either the second or the third such exascale machine in the United States, depending on the timing of the “El Capitan” system at Lawrence Livermore National Laboratory.

There were delays and setbacks on the road to exascale for all of these machines, as well as technology changes, ongoing competition with China, and other challenges. But don’t expect the next leap to zettascale – or even quantum computing – to be any quicker, according to Rick Stevens, associate laboratory director of computing for environment and life sciences at Argonne. Both could take another 15 to 20 years or more.

Such is the nature of HPC.

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A trio of theoretical physicists at the Pennsylvania State University has calculated the upper limit for the possible quantization of time—they suggest 10⁻³³ seconds as the upper limit for the period of a universal oscillator. In their paper published in the journal Physical Review Letters, Garrett Wendel, Luis Martínez and Martin Bojowald outline their theory and suggest a possible way to prove it.

For many years, theoretical physicists have been trying to explain a major problem—the general theory of relativity suggests that time is a continuous quantity, one that can move slower or faster depending on acceleration and gravity conditions. But quantum mechanics theories suggest that time ticks away at a steady pace, like the frames of a movie being played out. In this scenario, time must be universal. For both theories to be right, this contradiction must be explained in a rational way.

Continue reading “Theorists calculate upper limit for possible quantization of time” »

Excerpts from the Red Folder.

A surprise observation of negative mass in exciton–polaritons has added yet another dimension of weirdness to these strange light-matter hybrid particles.

Dr. Matthias Wurdack, Dr. Tinghe Yun and Dr. Eliezer Estrecho from the Department of Quantum Sciences and Technology (QST) were experimenting with exciton polaritons when they realized that under certain conditions the dispersion became inverted—equating to a negative mass.

To add to the surprise, the unexpected cause has turned out to be losses.

The exotic particles are called non-Abelian anyons, or nonabelions for short, and their Borromean rings exist only as information inside the quantum computer. But their linking properties could help to make quantum computers less error-prone, or more ‘fault-tolerant’ — a key step to making them outperform even the best conventional computers. The results, revealed in a preprint on 9 May¹, were obtained on a machine at Quantinuum, a quantum-computing company in Broomfield, Colorado, that formed as the result of a merger between the quantum computing unit of Honeywell and a start-up firm based in Cambridge, UK.

“This is the credible path to fault-tolerant quantum computing,” says Tony Uttley, Quantinuum’s president and chief operating officer.

Other researchers are less optimistic about the virtual nonabelions’ potential to revolutionize quantum computing, but creating them is seen as an achievement in itself. “There is enormous mathematical beauty in this type of physical system, and it’s incredible to see them realized for the first time, after a long time,” says Steven Simon, a theoretical physicist at the University of Oxford, UK.