ultracold atoms tagged posts

Scientists have created a miniature universe in the laboratory that could help answer one of the biggest mysteries in physics: What is time, and where does it come from? Using 24,000 ultracold atoms, a University of Birmingham researcher built an isolated quantum system that repeatedly expands and contracts, mimicking the Big Bang and a possible Big Crunch. Remarkably, the experiment showed that time could emerge from changes happening inside the system, without relying on an external clock.

What if time is not a fundamental part of the universe, but something that emerges from the changes taking place ins...

Scientists have built a quantum “wire” where atoms collide endlessly—but energy and motion never slow down. Researchers at TU Wien have discovered a quantum system where energy and mass move with perfect efficiency. In an ultracold gas of atoms confined to a single line, countless collisions occur—but nothing slows down. Instead of diffusing like heat in metal, motion travels cleanly and undiminished, much like a Newton’s cradle. The finding reveals a striking form of transport that breaks the usual rules of resistance.

In everyday physics, transport describes how things move from one place to another. Electric charge flows through wires, heat spreads through metal, and water travels through pipes...

Universe’s coldest fermions open portal to high-symmetry quantum realm. Japanese and U.S. physicists have used atoms about 3 billion times colder than interstellar space to open a portal to an unexplored realm of quantum magnetism.

“Unless an alien civilization is doing experiments like these right now, anytime this experiment is running at Kyoto University it is making the coldest fermions in the universe,” said Rice University’s Kaden Hazzard, corresponding theory author of a studypublished today in Nature Physics. “Fermions are not rare particles. They include things like electrons and are one of two types of particles that all matter is made of.”

A Kyoto team led by study author Yoshiro Takahashi used lasers to cool its fermions, atoms of ytterbium, within about one-billiont...

The Cold Atom Lab (CAL) is the first facility in orbit to produce clouds of “ultracold” atoms, which can reach a fraction of a degree above absolute zero: -459ºF (-273ºC), the absolute coldest temperature that matter can reach. Nothing in nature is known to hit the temperatures achieved in laboratories like CAL, which means the orbiting facility is regularly the coldest known spot in the universe.

NASA’s Cold Atom Laboratory on the International Space Station is regularly the coldest known spot in the universe...