# Momentum-space nonsymmorphic symmetry meets higher-order topology

## TL;DR

This paper explores how nonsymmorphic symmetry in momentum space can lead to new types of 3D topological insulators with unique corner states.

## Contribution

The paper introduces a novel method to realize momentum-space nonsymmorphic symmetry using artificial crystals for higher-order topology.

## Key findings

- Alternating 0 and π fluxes in artificial crystals achieves the nonsymmorphic group Pnnn.
- This setup enables 3D octupole topological insulators with corner states.
- The work demonstrates a new approach to higher-order topology in momentum space.

## Abstract

Momentum-space nonsymmorphic group Pnnn has been achieved by alternating 0 and π fluxes in artificial crystals, enabling 3D octupole topological insulators with corner states.