Toggle light / dark theme

EPFL researchers have collaborated with colleagues at Harvard and ETH Zurich on a new thin-film circuit that, when connected to a laser beam, produces finely tailorable terahertz-frequency waves. The device opens up a world of potential applications in optics and telecommunications.

Researchers led by Cristina Benea-Chelmus in the Laboratory of Hybrid Photonics (HYLAB) in EPFL’s School of Engineering have taken a big step toward successfully exploiting the so-called terahertz gap, which lies between about 300 to 30,000 gigahertz (0.3 to 30 THz) on the electromagnetic spectrum. This range is currently something of a technological dead zone, describing frequencies that are too fast for today’s electronics and telecommunications devices, but too slow for optics and imaging applications.

Now, thanks to an extremely thin chip with an integrated photonic circuit made of , the HYLAB researchers and colleagues at ETH Zurich and Harvard University have succeeded not just in producing terahertz waves, but in engineering a solution for custom-tailoring their frequency, wavelength, amplitude, and phase.

Long before we had quantum computers, classical computers, or even calculus, an ancient Greek philosopher known as Zeno of Elea used thought experiments to probe apparent paradoxes. Zeno imagined an arrow flying through the air. At each instant of time, he reasoned, the arrow is stationary. If the arrow’s trajectory is entirely composed of stationary instants, how can the arrow ever move through space? Motion is impossible!

Zeno’s ancient arrow paradox has since evolved into a quantum thought experiment, “the quantum Zeno effect,” whereby we can freeze the state of quantum systems by continuously observing them. In the latest installment of our Quantum Paradoxes content series, I explain the quantum Zeno effect, and show how we can test it out using Qiskit on quantum computers. Read on to find out how this counterintuitive quantum freezing works, and how to create your own quantum freezer game — which even works with entangled qubits! All the code you need is in this Jupyter Notebook, and you’ll also find a detailed explanation in our latest Quantum Paradoxes video.

https://youtu.be/vfUn8cR-eXw.

A mix of computer simulations and gamma-ray burst observations shed new light on merging neutron stars.

Astronomers trawled through archival observations of short gamma-ray bursts (GRBs) and detected the rapid evolution of two merging neutron stars into a superheavy neutron star, which then collapsed into a black hole.

Two neutron stars merge to create a black hole.


The FAA said normal operations were “resuming gradually” after ordering a nationwide pause on all domestic departures until 9 a.m. on Wednesday morning following a computer failure that has impacted flights around the country.

“The ground stop has been lifted,” officials said at about 8:50 a.m. ET. “We continue to look into the cause of the initial problem”

Departures were resuming at about 8:15 a.m. ET at two of the nation’s busiest hubs — Newark and Atlanta — FAA officials said on Twitter, adding, “We expect departures to resume at other airports at 9 a.m. ET.”

A breakthrough in quantum research – the first detection of excitons (electrically neutral quasiparticles) in a topological insulator has been achieved by an international team of scientists collaborating within the Würzburg-Dresden Cluster of Excellence ct.qmat. This discovery paves the way for a new generation of light-driven computer chips and quantum technologies. It was enabled thanks to smart material design in Würzburg, the birthplace of topological insulators. The findings have been published in the journal Nature Communications.

<em>Nature Communications</em> is a peer-reviewed, open-access, multidisciplinary, scientific journal published by Nature Portfolio. It covers the natural sciences, including physics, biology, chemistry, medicine, and earth sciences. It began publishing in 2010 and has editorial offices in London, Berlin, New York City, and Shanghai.

One of the biggest achievements of quantum physics was recasting our vision of the atom. Out was the early 1900s model of a solar system in miniature, in which electrons looped around a solid nucleus. Instead, quantum physics showed that electrons live a far more interesting life, meandering around the nucleus in clouds that look like tiny balloons. These balloons are known as atomic orbitals, and they come in all sorts of different shapes—perfectly round, two-lobed, clover-leaf-shaped. The number of lobes in the balloon signifies how much the electron spins about the nucleus.

That’s all well and good for individual , but when atoms come together to form something solid—like a chunk of metal, say—the outermost electrons in the atoms can link arms and lose sight of the nucleus from where they came, forming many oversized balloons that span the whole chunk of metal. They stop spinning about their and flow through the metal to carry electrical currents, shedding the diversity of multi-lobed balloons.

Now, researchers at the Quantum Materials Center (QMC) at the University of Maryland (UMD), in collaboration with theorists at the Condensed Matter Theory Center (CMTC) and Joint Quantum Institute (JQI), have produced the first experimental evidence that one metal—and likely others in its class—have electrons that manage to preserve a more interesting, multi-lobed structure as they move around in a solid. The team experimentally studied the shape of these balloons and found not a uniform surface, but a complex structure. This unusual metal is not only fundamentally interesting, but it could also prove useful for building quantum computers that are resistant to noise.

Google has warned that growth in the use of Android in India may stall due to an antitrust order issued by the Indian antitrust watchdog last year over the U.S. company’s domination in the country.

The order, which was issued by the Competition Commission of India (CCI) in September, found that Google had abused its dominant position in the market for mobile operating systems by imposing restrictive contracts on mobile manufacturers.

The CCI ordered Google to change its contracts with manufacturers, allowing them more freedom to install rival apps and services on Android devices. According to a Reuters report, Google filed a challenge with India’s Supreme Court and said that the order would require some modifications of its existing contracts and new license agreements. It would alter the company’s existing arrangements with over 1,100 device manufacturers and thousands of app developers.