Before determining the correct quantum theory of gravity, researchers need to know if gravity is actually quantized. Experiments testing that assumption are now being developed.
Category: quantum physics
Current flows without heat loss in newly engineered fractional quantum material
A team of US researchers has unveiled a device that can conduct electricity along its fractionally charged edges without losing energy to heat. Described in Nature Physics, the work, led by Xiaodong Xu at the University of Washington, marks the first demonstration of a “dissipationless fractional Chern insulator,” a long-sought state of matter with promising implications for future quantum technologies.
The quantum Hall effect emerges when electrons are confined to a two-dimensional material, cooled to extremely low temperatures, and exposed to strong magnetic fields. Much like the classical Hall effect, it describes how a voltage develops across a material perpendicular to the direction of current flow. In this case, however, that voltage increases in discrete, or quantized steps.
Under even more extreme conditions, an exotic variant appears named the “fractional quantum Hall” (FQH) effect. Here, electrons no longer behave as independent particles but move collectively, giving rise to voltage steps that correspond to fractions of an electron’s charge. This unusual collective behavior unlocks a whole host of exotic properties, and has made such states particularly appealing for emerging quantum technologies.
Five ways quantum technology could shape everyday life
The unveiling by IBM of two new quantum supercomputers and Denmark’s plans to develop “the world’s most powerful commercial quantum computer” mark just two of the latest developments in quantum technology’s increasingly rapid transition from experimental breakthroughs to practical applications.
There is growing promise of quantum technology’s ability to solve problems that today’s systems struggle to overcome, or cannot even begin to tackle, with implications for industry, national security and everyday life.
So, what exactly is quantum technology? At its core, it harnesses the counterintuitive laws of quantum mechanics, the branch of physics describing how matter and energy behave at the smallest scales. In this strange realm, particles can exist in several states simultaneously (superposition) and can remain connected across vast distances (entanglement).
MIT Scientists Shrink Terahertz Light To Reveal Hidden Quantum “Jiggles”
The kind of light you use can reveal very different things about a material. Visible light mainly shows what is happening at the surface. X-rays can probe structures inside. Infrared light highlights the heat a material gives off.
Researchers at MIT have now turned to terahertz light to uncover quantum vibrations in a superconducting material, signals that scientists have not been able to observe directly until now.
Physicists Perform “Quantum Surgery” To Fix Errors While Computing
Quantum computers are often described as a glimpse of a faster, more powerful future. The catch is that today’s devices are fragile in a way ordinary computers are not. Their biggest headache is decoherence, the gradual loss of the delicate quantum behavior that makes them useful in the first place. When decoherence sets in, it can trigger two common kinds of mistakes: bit flips and phase flips.
A bit flip is the more intuitive problem. A qubit that should represent ‘0’ can unexpectedly behave like ‘1’. A phase flip is stranger but just as damaging. Even if a qubit stays in a superposition, the relationship between its components can suddenly switch, turning a positive phase into a negative one and scrambling the computation.
Physicists discover what controls the speed of quantum time
From the article:
…in copper, the transition was extremely fast, taking about 26 attoseconds.
In the layered materials TiSe₂ and TiTe₂, the same process slowed to between 140 and 175 attoseconds. In CuTe, with its chain-like structure, the transition exceeded 200 attoseconds. These findings show that the atomic scale shape of a material strongly affects how quickly a quantum event unfolds, with lower symmetry structures leading to longer transition times.
Time may feel smooth and continuous, but at the quantum level it behaves very differently. Physicists have now found a way to measure how long ultrafast quantum events actually last, without relying on any external clock. By tracking subtle changes in electrons as they absorb light and escape a material, researchers discovered that these transitions are not instantaneous and that their duration depends strongly on the atomic structure of the material involved.
Seeing the Quantum Butterfly Effect
A combined experimental and theoretical study reveals the emergence of quantum chaos in a complex system, suggesting that it can be described with a universal theoretical framework.
Consider the following thought experiment: Take all the air molecules in a thunderstorm and evolve them backward in time for an hour, effectively rewinding a molecular movie. Then slightly perturb the velocity directions of a few molecules and evolve the system forward again to the current moment. Because such systems are chaotic, microscopic perturbations in the past will lead to dramatically different futures. This “butterfly effect” also occurs in quantum systems. To observe it, researchers measure a mathematical entity called the out-of-time-ordered correlator (OTOC). Loosely speaking, the OTOC measures how quickly a system “forgets” its initial state. Unfortunately, the OTOC is notoriously difficult to measure because it typically requires experimental protocols that implement an effective many-body time reversal.
Laser‑written glass chip pushes quantum communication toward practical deployment
As quantum computers continue to advance, many of today’s encryption systems face the risk of becoming obsolete. A powerful alternative—quantum cryptography—offers security based on the laws of physics instead of computational difficulty. But to turn quantum communication into a practical technology, researchers need compact and reliable devices that can decode fragile quantum states carried by light.
A new study from teams at the University of Padua, Politecnico di Milano, and the CNR Institute for Photonics and Nanotechnologies shows how this goal can be approached using a simple material: borosilicate glass. As reported in Advanced Photonics, their work demonstrates a high-performance quantum coherent receiver fabricated directly inside glass using femtosecond laser writing. The approach provides low optical loss, stable operation, and broad compatibility with existing fiber-optic infrastructure—key factors for scaling quantum technologies beyond the laboratory.
Muon Knight shift reveals the behavior of superconducting electron pairs
Quantum materials and superconductors are difficult enough to understand on their own. Unconventional superconductors, which cannot be explained within the framework of standard theory, take the enigma to an entirely new level. A typical example of unconventional superconductivity is strontium ruthenate, SRO214, the superconductive properties of which were discovered by a research team that included Yoshiteru Maeno, who is currently at the Toyota Riken—Kyoto University Research Center.
The findings are published in the journal Physical Review Letters.
Debate over SRO214’s superconducting nature.