Edge states in disordered photonic graphene

Area of Science:

• Condensed matter physics
• Photonics
• Materials science

Background:

• Photonic graphene, a honeycomb waveguide lattice, exhibits unique edge states.
• Disorder is a critical factor influencing the properties of such systems.

Purpose of the Study:

• To investigate the distinct impacts of composite and structural disorder on photonic graphene's edge states.
• To determine how chiral symmetry influences edge state confinement under different disorder types.

Main Methods:

• Numerical simulations of photonic waveguide lattices.
• Experimental investigations using fabricated photonic graphene structures.

Main Results:

• Structural (off-diagonal) disorder preserves the zero-energy edge state confinement.
• Composite disorder leads to the loss of edge state confinement.
• Chiral symmetry plays a key role in maintaining edge state integrity against structural disorder.

Conclusions:

• The type of disorder significantly affects the robustness of edge states in photonic graphene.
• Structural disorder offers a pathway to robust edge states due to preserved chiral symmetry, unlike composite disorder.