Synopsis: One relation to rule them all

Data continue to accumulate showing that an important set of universal relations accurately describes the properties of ultracold fermionic gases.
Synopsis figure
Illustration: Alan Stonebraker

Quantum gases of ultracold fermions offer a versatile way to study phenomena from quark matter to superconductors. In 2008, Shina Tan (then at the University of Washington) published a set of exact universal relations connecting microscopic quantities with thermodynamic variables under a wide range of conditions. Recently, a group at JILA experimentally verified some of the Tan relations in ultracold potassium-40 [1]. Writing in Physical Review Letters, Eva Kuhnle and colleagues at Swinburne University of Technology in Melbourne, Australia, now add to the picture with their results on lithium-6.

Kuhnle et al. used Bragg scattering of atoms from a periodic optical potential to verify one of the Tan relations for pair correlations as a function of both the scattering length and probe momentum. This complements the JILA work, which verified a relation between total energy and adiabatic changes in scattering length, and another relation that extends the virial theorem (which expresses total energy in terms of kinetic energy, external potential energy, and interaction energy) to quantum gases. – David Voss

[1] J. T. Stewart, J. P. Gaebler, T. E. Drake, and D. S. Jin, Phys. Rev. Lett. 104, 235301 (2010); see also Viewpoint commentary by D. Sheehy, Physics 3, 48 (2010).


Announcements

More Announcements »

Subject Areas

Atomic and Molecular Physics

Next Synopsis

Nuclear Physics

Order out of chaos

Read More »

Related Articles

Viewpoint: Bose Polarons that Strongly Interact
Atomic and Molecular Physics

Viewpoint: Bose Polarons that Strongly Interact

Researchers have used impurities within a Bose-Einstein condensate to simulate polarons—electron-phonon combinations in solid-state systems. Read More »

Synopsis: Taking Pictures with Single Ions
Atomic and Molecular Physics

Synopsis: Taking Pictures with Single Ions

A new ion microscope with nanometer-scale resolution builds up images using single ions emitted one at a time from an ion trap. Read More »

Viewpoint: Squeezed Light Reengineers Resonance Fluorescence
Atomic and Molecular Physics

Viewpoint: Squeezed Light Reengineers Resonance Fluorescence

By bathing a superconducting qubit in squeezed light, researchers have been able to confirm a decades-old prediction for the resulting phase-dependent spectrum of resonance fluorescence. Read More »

More Articles