ultracold atoms tagged posts

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...

An expanding, ring-shaped cloud of atoms shares several striking features with the early universe. (Credit: E. Edwards/JQI)

An expanding cloud of atoms could offer insight into unanswered cosmological questions. Researchers playing with a cloud of ultracold atoms uncovered behavior that bears a striking resemblance to the universe in microcosm. Their work, which forges new connections between atomic physics and the sudden expansion of the early universe, will be published in Physical Review X and highlighted by Physics.8

“From the atomic physics perspective, the experiment is beautifully described by existing theory,” says Stephen Eckel, an atomic physicist at the National Institute of Standards and Technology (NIST). “But even more striking is how that theory connects with cosmology.”

In ...

The wavelike pattern at the top shows the accordion-like structure of a proposed quantum material—an artificial crystal made of light—that can trap atoms in regularly spaced nanoscale pockets. These pockets can be made to hold a large collection of ultracold “host” atoms (green), slowed to a standstill by laser light, and individually planted “probe” atoms (red) that can be made to transmit quantum information in the form of a photon (particle of light). The lower panel shows how the artificial crystal can be reconfigured with light from an open (hyperbolic, in orange) geometry to a closed (elliptical, in green) geometry, which greatly affects the speed at which the probe atom can release a photon. Credit: Pankaj K. Jha/UC Berkeley

Scientists have devised a way to build a “quan...