Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: quantum physics – Page 19

X-ray four-wave mixing captures elusive electron interactions inside atoms and molecules

Scientists at the X-ray free-electron laser SwissFEL have realized a long-pursued experimental goal in physics: to show how electrons dance together. The technique, known as X-ray four-wave mixing, opens a new way to see how energy and information flow within atoms and molecules. In the future, it could illuminate how quantum information is stored and lost, eventually aiding the design of more error-tolerant quantum devices. The findings are reported in Nature.

Much of the behavior of matter arises not from electrons acting alone, but from the ways they influence each other. From chemical systems to advanced materials, their interactions shape how molecules rearrange, how materials conduct or insulate and how energy flows.

In many quantum technologies —not least quantum computing—information is stored in delicate patterns of these interactions, known as coherences. When these coherences are lost, information disappears—a process known as decoherence. Learning how to understand and ultimately control such fleeting states is one of the major challenges facing quantum technologies today.

Turning crystal flaws into quantum highways: A new route towards scalable solid-state qubits

Building large-scale quantum technologies requires reliable ways to connect individual quantum bits (qubits) without destroying their fragile quantum states. In a new theoretical study, published in npj Computational Materials, researchers show that crystal dislocations—line defects long regarded as imperfections—can instead serve as powerful building blocks for quantum interconnects.

Using advanced first-principles simulations, a team led by Prof. Maryam Ghazisaeidi at The Ohio State University and Prof. Giulia Galli at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) and Chemistry Department demonstrated that nitrogen-vacancy (NV) centers in diamond, a leading solid-state qubit platform, can be attracted to dislocations and retain—and in some cases improve—their quantum properties when positioned near these line defects.

“Because dislocations form quasi-one-dimensional (1D) structures extending through a crystal, they provide a natural scaffold for arranging qubits into ordered arrays,” said co-first author Cunzhi Zhang, a UChicago PME staff scientist in the Galli Group.

Wormholes may not exist—we’ve found they reveal something deeper about time and the universe

Wormholes are often imagined as tunnels through space or time—shortcuts across the universe. But this image rests on a misunderstanding of work by physicists Albert Einstein and Nathan Rosen.

In 1935, while studying the behavior of particles in regions of extreme gravity, Einstein and Rosen introduced what they called a “bridge”: a mathematical link between two perfectly symmetrical copies of spacetime. It was not intended as a passage for travel, but as a way to maintain consistency between gravity and quantum physics. Only later did Einstein–Rosen bridges become associated with wormholes, despite having little to do with the original idea.

But in new research published in Classical and Quantum Gravity, my colleagues and I show that the original Einstein–Rosen bridge points to something far stranger—and more fundamental—than a wormhole.

Perovskite display technology demonstrates record efficiency and industry-level operational lifetime

A research team has developed a hierarchical-shell perovskite nanocrystal technology that simultaneously overcomes the long-standing instability of metal-halide perovskite emitters while achieving record-breaking quantum yield, operational stability, and scalability. This work paves the way for next-generation vivid-color display technologies.

The research is published in the journal Science as a cover article.

The team was led by Professor Tae-Woo Lee (Department of Materials Science and Engineering, Seoul National University, Republic of Korea & SN Display Co., Ltd).

New spectroscopic method reveals ion’s complex nuclear structure

Different atoms and ions possess characteristic energy levels. Like a fingerprint, they are unique for each species. Among them, the atomic ion 173 Yb+ has attracted growing interest because of its particularly rich energy structure, which is promising for applications in quantum technologies and searches for so-called new physics. On the flip side, the complex structure that makes 173 Yb+ interesting has long prevented detailed investigations of this ion.

Now, researchers from PTB, TU Braunschweig, and the University of Delaware have taken a closer look at the ion’s energy structure. To achieve this, they trapped a single 173 Yb+ ion and developed methods for preparing and detecting its energy state despite the complicated energy structure. This enabled high-resolution laser and microwave spectroscopy. The research is published in the journal Physical Review Letters.

In particular, the researchers investigated energy shifts arising from interactions between the nucleus and its surrounding electrons, also called hyperfine structure. Combined with first-principle theory calculations, the precise measurement results yielded new information about the ion’s nucleus.

Efficient cooling method could enable chip-based quantum computers

Quantum computers could rapidly solve complex problems that would take the most powerful classical supercomputers decades to unravel. But they’ll need to be large and stable enough to efficiently perform operations. To meet this challenge, researchers at MIT and elsewhere are developing quantum computers based on ultra-compact photonic chips. These chip-based systems offer a scalable alternative to some existing quantum computers, which rely on bulky optical equipment.

These quantum computers must be cooled to extremely cold temperatures to minimize vibrations and prevent errors. So far, such chip-based systems have been limited to inefficient and slow cooling methods.

Now, a team of researchers at MIT and MIT Lincoln Laboratory has implemented a much faster and more energy-efficient method for cooling these photonic chip-based quantum computers. Their approach achieved cooling to about 10 times below the limit of standard laser cooling.

New state of matter discovered in a quantum material

At TU Wien, researchers have discovered a state in a quantum material that had previously been considered impossible. The definition of topological states should be generalized.

The work is published in Nature Physics.

Quantum physics tells us that particles behave like waves and, therefore, their position in space is unknown. Yet in many situations, it still works remarkably well to think of particles in a classical way—as tiny objects that move from place to place with a certain velocity.

Neutral-atom arrays, a rapidly emerging quantum computing platform, get a boost from researchers

For quantum computers to outperform their classical counterparts, they need more quantum bits, or qubits. State-of-the-art quantum computers have around 1,000 qubits. Columbia physicists Sebastian Will and Nanfang Yu have their sights set much higher.

“We are laying critical groundwork to enable quantum computers with more than 100,000 qubits,” Will said.

In a paper published in Nature, Will, Yu, and their colleagues combine two powerful technologies— optical tweezers and metasurfaces—to dramatically scale the size of neutral-atom arrays.

/* */