Quantum phase transition for the BEC--BCS crossover in condensed matter physics and CPT violation in elementary particle physics

TL;DR

This paper explores a quantum phase transition in condensed matter systems related to the BEC-BCS crossover and discusses its implications for CPT violation and neutrino oscillations in elementary particle physics.

Contribution

It introduces the concept of a quantum phase transition involving Fermi point splitting in both condensed matter and particle physics contexts.

Findings

Fermi point splitting can occur in ultracold fermionic atoms during BEC-BCS crossover

Fermi point splitting may lead to CPT violation and neutrino oscillations

The transition separates fully-gapped and topologically-protected Fermi point states

Abstract

We discuss the quantum phase transition that separates a vacuum state with fully-gapped fermion spectrum from a vacuum state with topologically-protected Fermi points (gap nodes). In the context of condensed-matter physics, such a quantum phase transition with Fermi point splitting may occur for a system of ultracold fermionic atoms in the region of the BEC-BCS crossover, provided Cooper pairing occurs in the non-s-wave channel. For elementary particle physics, the splitting of Fermi points may lead to CPT violation, neutrino oscillations, and other phenomena.