Encyclopedia of emergent particles in three-dimensional crystals

TL;DR

This paper provides a comprehensive classification of all possible emergent particles in three-dimensional, time-reversal invariant condensed matter systems, aiding future discovery and engineering of novel quasiparticles.

Contribution

It offers a complete list of emergent particles derived from systematic symmetry analysis, covering both spinful and spinless particles in various physical systems.

Findings

Complete enumeration of emergent particles in 3D time-reversal-invariant systems

Established correspondence between particles, symmetry, models, and topology

Guidance for experimental realization of novel particles

Abstract

The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems. Novel particles, emerged as excitations around exotic band degeneracy points, continue to be reported in real materials and artificially engineered systems, but so far, we do not have a complete picture on all possible types of particles that can be achieved. Here, via systematic symmetry analysis and modeling, we accomplish a complete list of all possible particles in time reversal-invariant systems. This includes both spinful particles such as electron quasiparticles in solids, and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks. We establish detailed correspondence between the particle, the symmetry condition, the effective model, and the topological character. This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems.