Novel Materials Could Help Terahertz Chips Deliver Data at Terabits-Per-Second Rates

Novel materials known as photonic topological insulators could one day help terahertz waves send data across chips at unprecedented speeds of a trillion bits per second, a new study finds.

Terahertz waves fall between optical waves and microwaves on the electromagnetic spectrum. Ranging in frequency from 0.1 to 10 terahertz, terahertz waves could be key to future 6G wireless networks. With those networks, engineers aim to transmit data at terabits (trillions of bits) per second.

Such data links could also greatly boost intra-chip and inter-chip communication to support artificial intelligence (AI) and cloud-based technologies, such as autonomous driving.

“Artificial intelligence and cloud-based applications require high volumes of data to be transmitted to a connected device with ultra-high-speed and low latency,” says Ranjan Singh, a photonics researcher at Nanyang Technological University in Singapore and coauthor of the new work. “Take for example, an autonomous vehicle that uses AI to make decisions. In order to increase the efficiency of decision-making tasks, the AI-sensors need to receive data from neighboring vehicles at ultra-high speed to perform the actions in real time.”

Conventional terahertz waveguides are vulnerable to fabrication defects and considerable signal loss at sharp bends. Now, researchers find the burgeoning field of topological photonics may help solve these problems.

Topology is the branch of mathematics that explores what features of shapes can survive deformation. For instance, an object shaped like a doughnut can get pushed and pulled into the shape of a mug, with the doughnut’s hole forming the hole in the cup’s handle, but it could not get deformed into a shape that lacked a hole without ripping the item apart.

Using insights from topology, researchers developed the first electronic topological insulators in 2007. Electrons traveling along the edges or surfaces of these materials strongly resist any disturbances that might hamper their flow, much as a doughnut might resist any change that would remove its hole.

Recently, scientists have designed photonic topological insulators in which photons of light are similarly “topologically protected.” These materials possess regular variations within their structures that lead specific wavelengths of light to flow within them without scattering or losses, even around corners and imperfections. [READ MORE]