Studies of braided non-Abelian anyons using anyonic tensor networks

TL;DR

This thesis develops advanced tensor network algorithms for simulating non-Abelian anyons and applies them to study their topological phases and phase diagrams, revealing new phases influenced by anyon exchange statistics.

Contribution

It introduces U(1)-symmetric anyonic tensor networks and proposes the anyonic Hubbard model to explore non-Abelian anyon phases.

Findings

Discovered new phases of matter from anyon interactions and braiding.

Extended tensor network algorithms to include U(1) symmetry.

Analyzed phase diagrams of Fibonacci and Ising anyons.

Abstract

The content of this thesis can be broadly summarised into two categories: first, I constructed modified numerical algorithms based on tensor networks to simulate systems of anyons in low dimensions, and second, I used those methods to study the topological phases the anyons form when they braid around one another. In the first phase of my thesis, I extended the anyonic tensor network algorithms, by incorporating U(1) symmetry to give a modified ansatz, Anyon-U(1) tensor networks, which are capable of simulating anyonic systems at any rational filling fraction. In the second phase, I used the numerical methods to study some models of non-Abelian anyons that naturally allows for exchange of anyons. I proposed a lattice model of anyons, which I dubbed anyonic Hubbard model, which is a pair of coupled chains of anyons (or simply called anyonic ladder). Each site of the ladder can either host a single anyonic charge, or it can be empty. The anyons are able to move around, interact with one another, and exchange positions with other anyons, when vacancies exist. Exchange of anyons is a non-trivial process which may influence the formation of different kinds of new phases of matter. I studied this model using the two prominent species of anyons: Fibonacci and Ising anyons, and made a number of interesting discoveries about their phase diagrams. I identified new phases of matter arising from both the interaction between these anyons and their exchange braid statistics.