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Quantum computing has long struggled with creating entangled photons efficiently, but a team of researchers has discovered a game-changing method using metasurfaces—flat, engineered structures that control light.

By leveraging these metasurfaces, they can generate and manipulate entangled photons more easily and compactly than ever before. This breakthrough could open the door to smaller, more powerful quantum computers and even pave the way for quantum networks that deliver entangled photons to multiple users.

Revolutionizing Quantum Information Processing.

By miniaturizing cold atom trapping with integrated photonics, researchers are making quantum technologies portable. Their photonic chip system replaces traditional free-space optics, offering a path toward highly precise, deployable quantum sensors and computing tools. Bringing Quantum Experime.

Researchers from the Department of Physics have managed to experimentally develop a new magnetic state: a magneto-ionic vortex or “vortion.” The research, published in Nature Communications, allows for an unprecedented level of control of magnetic properties at the nanoscale and at room temperature, and opens new horizons for the development of advanced magnetic devices.

The use of Big Data has multiplied the energy demand in information technologies. Generally, to store information, systems utilize electric currents to write data, which dissipates power by heating the devices. Controlling magnetic memories with voltage, instead of , can minimize this energy expenditure.

One way to achieve this is by using magneto-ionic materials, which allow for the manipulation of their magnetic properties by adding or removing ions through changes in the polarity of the applied voltage. So far, most studies in this area have focused on continuous films, rather than on controlling properties at the nanometric scale in discrete “bits,” essential for high-density data storage.

“I give you God’s view,” said Toby Cubitt, a physicist turned computer scientist at University College London and part of the vanguard of the current charge into the unknowable, and “you still can’t predict what it’s going to do.”

Eva Miranda, a mathematician at the Polytechnic University of Catalonia (UPC) in Spain, calls undecidability a “next-level chaotic thing.”

Undecidability means that certain questions simply cannot be answered. It’s an unfamiliar message for physicists, but it’s one that mathematicians and computer scientists know well. More than a century ago, they rigorously established that there are mathematical questions that can never be answered, true statements that can never be proved. Now physicists are connecting those unknowable mathematical systems with an increasing number of physical ones and thereby beginning to map out the hard boundary of knowability in their field as well.

Newly achieved precise control over light emitted from incredibly tiny sources, a few nanometers in size, embedded in two-dimensional (2D) materials could lead to remarkably high-resolution monitors and advances in ultra-fast quantum computing, according to an international team led by researchers at Penn State and Université Paris-Saclay.

In a recent study, published in ACS Photonics, scientists worked together to show how the light emitted from 2D materials can be modulated by embedding a second 2D material inside them—like a tiny island of a few nanometers in size—called a nanodot. The team described how they achieved the confinement of nanodots in two dimensions and demonstrated that, by controlling the nanodot size, they could change the color and frequency of the emitted light.

“If you have the opportunity to have localized from these materials that are relevant in quantum technologies and electronics, it’s very exciting,” said Nasim Alem, Penn State associate professor of materials science and engineering and co-corresponding author on the study. “Envision getting light from a zero-dimensional point in your field, like a dot in space, and not only that, but you can also control it. You can control the frequency. You can also control the wavelength where it comes from.”

In a material made of two thin crystal layers that are slightly twisted with respect to each other, researchers at ETH have studied the behavior of strongly interacting electrons. Doing so, they found a number of surprising properties.

Many modern technologies are based on special materials, such as the semiconductors that are important for computers, inside of which can move more or less freely. Exactly how free those electrons are is determined by their quantum properties and the crystal structure of the material. Most of the time they move independently of each other. Under certain conditions, however, between the electrons can give rise to particular phenomena. Superconductors, in which electrons pair up to conduct electrical current without resistance, are a well-known example.

At the Institute for Quantum Electronics in Zurich, ETH-professor Ataç Imamoğlu investigates materials with strongly interacting electrons. He wants to understand the behavior of the electrons in those materials better and looks for unexpected properties that might be interesting for future applications. In a “twisted” material, he and his collaborators have now made some surprising discoveries regarding the behavior of electrons, as they report in the scientific journal Nature.

A team of researchers has developed the first chip-scale titanium-doped sapphire laser—a breakthrough with applications ranging from atomic clocks to quantum computing and spectroscopic sensors.

The work was led by Hong Tang, the Llewellyn West Jones, Jr. Professor of Electrical Engineering, Applied Physics & Physics. The results are published in Nature Photonics.

When the titanium-doped laser was introduced in the 1980s, it was a major advance in the field of lasers. Critical to its success was the material used as its gain medium—that is, the material that amplifies the laser’s energy. Sapphire doped with titanium ions proved to be particularly powerful, providing a much wider laser emission bandwidth than conventional semiconductor lasers. The innovation led to fundamental discoveries and countless applications in physics, biology, and chemistry.