Cubic 3D Chern photonic insulators with orientable large Chern vectors

Area of Science:

• Topological photonics
• Condensed matter physics

Background:

• Topological phases with broken time-reversal symmetry (TRS) offer robust surface states.
• While 2D topological phases are well-studied, 3D systems with broken TRS are rare.

Purpose of the Study:

• To devise a general strategy for designing 3D Chern insulating (3D CI) cubic photonic crystals.
• To achieve orientable and arbitrarily large Chern vectors in a weakly TRS broken environment.

Main Methods:

• Design of 3D cubic photonic crystals.
• Utilizing a weakly broken time-reversal symmetry environment.
• Engineering Chern vectors for specific topological properties.

Main Results:

• Demonstrated topologically protected chiral and unidirectional surface states.
• Showcased disjoint equifrequency loops for surface states.
• Established that increasing the Chern number supports multiple surface state channels.
• Showed Chern vector orientation is controllable via magnetization axis.
• Achieved designs suitable for weak magnetic response applications.

Conclusions:

• The proposed strategy enables the creation of versatile 3D Chern insulators.
• The designs facilitate enhanced 3D CI/3D CI interfacing possibilities.
• The system is well-suited for practical photonic applications due to relaxed TRS breaking requirements.