Category Physics

This microscopic closeup shows a small sample of ytterbium dirhodium disilicide, one of the most-studied “heavy fermion” composites. The scale bar in the center of the screen is one millimeter wide. Credit: Marc Tippmann/Technical University of Munich

Physicists have made a surprising discovery that the arrangement of atomic nuclei spins helps bring about superconductivity in ytterbium dirhodium disilicide, one of the most-studied materials in a class of quantum critical compounds known as ‘heavy fermions.’ It provides further evidence that unconventional superconductivity arises from “quantum criticality.”

“There is already compelling evidence that unconventional superconductivity is linked in both copper-based and iron-based high-temperature superconductors to quantum fluctuations that a...

Associate Professor Joan Vaccaro, of Griffith University’s Centre for Quantum Dynamics Credit: Griffith University

New research from Griffith University’s Centre for Quantum Dynamics is broadening perspectives on time and space. A/Prof Joan Vaccaro challenges the long-held presumption that time evolution—the incessant unfolding of the universe over time—is an elemental part of Nature. She suggests there may be a deeper origin due to a difference between the directions of time: to the future and to the past.

“If you want to know where the universe came from and where it’s going, you need to know about time,” says Associate Professor Vaccaro.
“Experiments on subatomic particles over the past 50 years ago show that Nature doesn’t treat both directions of time equally...

Dr Jon Prance at the Lancaster Quantum Technology Centre. Credit: Image courtesy of Lancaster University

The 1st ever measurement of the temp of electrons in a nanoelectronic device a few thousandths of a degree above 0K was demonstrated in a joint research project performed by Lancaster University, VTT Technical Research Centre of Finland Ltd, and Aivon Ltd. The team managed to make the electrons in a circuit on a silicon chip colder than had previously been achieved. Dr Rich Haley said: “This is a notable achievement in that the team has finally broken through the 4 millikelvin barrier, which has been the record in such structures for over 15 years.”

Although it has long been possible to cool samples of bulk metals even below 1 millikelvin, it has proved very difficult to transfer this t...