PIRSA:21020003

# New routes to topological order: Toric code order in Rydberg atoms and fractional Chern insulators in moire materials

### APA

Vishwanath, A. (2021). New routes to topological order: Toric code order in Rydberg atoms and fractional Chern insulators in moire materials. Perimeter Institute. https://pirsa.org/21020003

### MLA

Vishwanath, Ashvin. New routes to topological order: Toric code order in Rydberg atoms and fractional Chern insulators in moire materials. Perimeter Institute, Feb. 22, 2021, https://pirsa.org/21020003

### BibTex

@misc{ pirsa_21020003, doi = {10.48660/21020003}, url = {https://pirsa.org/21020003}, author = {Vishwanath, Ashvin}, keywords = {Condensed Matter}, language = {en}, title = {New routes to topological order: Toric code order in Rydberg atoms and fractional Chern insulators in moire materials}, publisher = {Perimeter Institute}, year = {2021}, month = {feb}, note = {PIRSA:21020003 see, \url{https://pirsa.org}} }

Ashvin Vishwanath Harvard University

**Talk Type**Scientific Series

**Subject**

## Abstract

### Despite decades of theoretical work, the physical realization of topological order, outside of the fractional quantum Hall effect, has proved to be an elusive goal. Even the simplest example of a time-reversal symmetric topological order, as encountered in the paradigmatic toric code, awaits experimental realization. Key challenges include the lack of physically realistic models in these phases, and of ways to probe their defining properties. I will discuss a simple `Rydberg blockade' model, and describe numerical results that point to (i) a ground state with toric code topological order that could potentially be realized in experiment and (ii) ``smoking gun'' signatures of the phase which be accessed using a dynamic protocol. I will also briefly discuss how a topological qubit can be constructed in this platform by tuning boundaries as well as implications for constructing fault-tolerant quantum memories. Time permitting, a different platform for realizing exotic phases, magic-angle graphene and the special features of its band structure will be described, which make it a prime candidate for realizing fractional quantum Hall topological order even in the absence of a magnetic field.

References: arXiv:2011.12310. and arXiv:1912.09634