Field theory in superfluid 3He: What are the lessons for particle physics, gravity and high-temperature superconductivity?

TL;DR

This paper explores how superfluid 3He-A's topological fermionic quasiparticles serve as analogs for phenomena in particle physics and gravity, providing insights into high-energy physics and high-temperature superconductivity through condensed matter experiments.

Contribution

It identifies superfluid 3He-A as a topological class with chiral quasiparticles, linking condensed matter phenomena to fundamental physics and proposing experimental simulations of complex high-energy processes.

Findings

Superfluid 3He-A quasiparticles are topologically protected chiral fermions.

Textures in 3He-A induce effective metrics simulating gravitational fields.

High-temperature superconductors may exhibit similar topological properties.

Abstract

There are several classes of homogeneous Fermi-systems which are characterized by the topology of the energy spectrum of fermionic quasiparticles: (1) Gapless systems with a Fermi-surface; (2) Systems with a gap in their spectrum; (3) Gapless systems with topologically stable point nodes (Fermi points); and (4) Gapless systems with topologically unstable lines of nodes (Fermi lines). Superfluid 3He-A and electroweak vacuum belong to the universality Class (3). The fermionic quasiparticles (particles) in this class are chiral: they are left-handed or right-handed. The collective bosonic modes of systems of Class (3) are the effective gauge and gravitational fields. The great advantage of superfluid 3He-A is that we can perform experiments using this condensed matter and thereby simulate many phenomena in high energy physics, including axial anomaly, baryoproduction, and magnetogenesis. 3He-A textures induce a nontrivial effective metrics of the space, where the free quasiparticles move along geodesics. With 3He-A one can simulate event horizons, Hawking radiation, rotating vacuum, etc. High-temperature superconductors are believed to belong to Class (4). They have gapless fermionic quasiparticles with a "relativistic" spectrum close to gap nodes, which allows application of ideas developed for superfluid 3He-A.