Distinct from other insulator materials, topological insulator materials are able to transport electric signals without dissipation. “Three-dimensional (3D) topological insulators have important capabilities, including the ability to channel topological surface states along all possible spatial directions,” explains project co-lead Assoc Prof Zhang Baile.
For years, researchers have attempted to build 3D topological insulators for photons, which have various applications in optical devices.
Using a stack of thin plastic sheets embedded with metal antennas acting as tiny electromagnetic resonators, a team from NTU’s School of Physical and Mathematical Sciences and China’s Zhejiang University created the world’s first 3D photonic topological insulator.
Though their 3D photonic topological insulator is limited to low-frequency electromagnetic waves such as microwaves, the researchers are targeting optical frequencies like those of visible light for applications in optical computer chips, lasers and other optical devices.