Category Physics

When a crystal is just one atom thick, melting gets weird — and scientists have finally caught it on camera.
When materials become just one atom thick, melting no longer follows the familiar rules. Instead of jumping straight from solid to liquid, an unusual in-between state emerges, where atomic positions loosen like a liquid but still keep some solid-like order. Scientists at the University of Vienna have now captured this elusive “hexatic” phase in real time by filming an ultra-thin silver iodide crystal as it melted inside a protective graphene sandwich.

When ice t...

Physical systems become inherently more complicated and difficult to produce in a lab as the number of dimensions they exist in increases—even more so in quantum systems. While discrete time crystals (DTCs) had been previously demonstrated in one dimension, two-dimensional DTCs were known to exist only theoretically. But now, a new study, published in Nature Communications, has demonstrated the existence of a DTC in a two-dimensional system using a 144-qubit quantum processor.

What is a discrete time crystal?
Like regular crystalline materials, DTCs exhibit a kind of periodicity...

A long-standing law of thermodynamics turns out to have a loophole at the smallest scales. Researchers have shown that quantum engines made of correlated particles can exceed the traditional efficiency limit set by Carnot nearly 200 years ago. By tapping into quantum correlations, these engines can produce extra work beyond what heat alone allows. This could reshape how scientists design future nanoscale machines.

Two physicists at the University of Stuttgart have demonstrated that the Carnot principle, a foundational rule of thermodynamics, does not fully apply at the atomic scale when particles are physically linked (so-called correlated objects). Their findings suggest that this long-standing limit on efficiency breaks down for tiny systems governed by quantum effects...