# Crystal-to-Fracton Tensor Gauge Theory Dualities

## TL;DR

This paper establishes duality mappings between 2D crystal elasticity and fracton tensor gauge theories, revealing new insights into phase diagrams, quantum melting, and supersolid phases through a unified gauge theory framework.

## Contribution

It introduces explicit dualities between crystal elasticity and fracton gauge theories, including extensions to quantum and bosonic systems, and explores implications for phase transitions and topological orders.

## Key findings

- Duality maps crystal phonons to gauge modes.
- Topological defects correspond to fracton charges.
- Predicts phase diagrams and melting transitions.

## Abstract

We demonstrate several explicit duality mappings between elasticity of two-dimensional crystals and fracton tensor gauge theories, expanding on recent works by two of the present authors. We begin by dualizing the quantum elasticity theory of an ordinary commensurate crystal, which maps directly onto a fracton tensor gauge theory, in a natural tensor analogue of the conventional particle-vortex duality transformation of a superfluid. The transverse and longitudinal phonons of a crystal map onto the two gapless gauge modes of the tensor gauge theory, while the topological lattice defects map onto the gauge charges, with disclinations corresponding to isolated fractons and dislocations corresponding to dipoles of fractons. We use the classical limit of this duality to make new predictions for the finite-temperature phase diagram of fracton models, and provide a simpler derivation of the Halperin-Nelson-Young theory of thermal melting of two-dimensional solids. We extend this duality to incorporate bosonic statistics, which is necessary for a description of the quantum melting transitions. We thereby derive a hybrid vector-tensor gauge theory which describes a supersolid phase, hosting both crystalline and superfluid orders. The structure of this gauge theory puts constraints on the quantum phase diagram of bosons, and also leads to the concept of symmetry enriched fracton order. We formulate the extension of these dualities to systems breaking time-reversal symmetry. We also discuss the broader implications of these dualities, such as a possible connection between fracton phases and the study of interacting topological crystalline insulators.