Hanns-Christoph Nägerl

Stories

Bethe strings, predicted in 1931, created in ultracold cesium gas

Active at the University of Innsbruck

A quantum state predicted in 1931 now exists in a laboratory. Physicists in Innsbruck cooled cesium atoms near absolute zero, squeezed them into thousands of one-dimensional tubes, and watched them bind into clusters called Bethe strings.

Updated Oct 28

Physicists create a strange new quantum state called a fractional Fermi sea

New Capabilities

Led the study reporting the fractional Fermi sea

Physicists at the University of Innsbruck created a new quantum state called a fractional Fermi sea: ultracold cesium atoms locked into a highly excited but orderly configuration. The state forms when researchers cycle the atoms between forceful repulsion and attraction, pushing the gas far from equilibrium without letting it fall into disorder.

Updated Oct 19

Notable Quotes

Transiently you create these Bethe string states. But I don't think they are long-lived.

from Bethe strings, predicted in 1931, created in ultracold cesium gas · Updated Oct 28

"This state is highly excited, but it is not random. It has a hidden order that becomes visible in its correlations."

from Physicists create a strange new quantum state called a fractional Fermi sea · Updated Oct 19

"We are not yet sure how we should name these new quasiparticles. Perhaps 'super-Fermions'?"

from Physicists create a strange new quantum state called a fractional Fermi sea · Updated Oct 19

"The discovery of fractional Fermi seas shows how far we can push quantum simulation: not only reproducing known models, but creating and probing states that go beyond established paradigms."

from Physicists create a strange new quantum state called a fractional Fermi sea · Updated Oct 19