Verification of universal relations in a strongly interacting Fermi gas

Understand

Many-body fermion systems are important in many branches of physics, including condensed matter, nuclear, and now cold atom physics.

• In many cases, the interactions between fermions can be approximated by a contact interaction.
• A recent theoretical advance in the study of these systems is the derivation of a number of exact universal relations that are predicted to be valid for all interaction strengths, temperatures, and spin compositions.
• These equations, referred to as the Tan relations, relate a microscopic quantity, namely, the amplitude of the high-momentum tail of the fermion momentum distribution, to the thermodynamics of the many-body system.