Breakthrough uses 2D materials to harness terahertz for next-gen wireless.

A wireless revolution is coming – one that could make today's fastest networks feel like dial-up. Using nanomaterials to manipulate ultra-high-frequency signals, scientists have discovered a method of tapping into an unused spectrum of wireless wavelengths that opens the door to even faster communications technology speeds.

Right now, the cutting edge of wireless connectivity is built on 5G networks, offering peak speeds of up to 10 gigabits per second – though in real-world conditions, speeds are often much lower. While 5G is a major step forward, it still struggles with coverage, consistency, and capacity, especially as demand for high-speed data continues to grow.

Streaming, Internet of Things devices, AI-driven applications, cloud computing, immersive digital environments, and Industry 4.0 are just some of the major forces increasing demand for high-speed, low-latency wireless connectivity – revealing the limits of 5G and the need for more advanced solutions.

To push past these limitations, researchers have moved beyond gigahertz into the terahertz spectrum – an untapped range of frequencies that could drastically increase wireless speeds. Though terahertz frequencies offer incredible potential, they have been notoriously difficult to harness due to signal loss and inefficiency.

Now, researchers at the University of Ottawa have made a breakthrough using graphene, a nanomaterial with exceptional electrical and optical properties, to more efficiently convert and control terahertz signals – a crucial step toward making this technology viable for real-world communication systems.

Information highway

All wireless communication relies on electromagnetic waves, which are divided into frequency bands based on how fast they oscillate, meaning moving up and down like a literal wave.

These waves are generated when electrical energy is fed into an antenna, creating invisible signals that radiate outward to carry information, with the speed of their oscillations measured in hertz (Hz) – lower frequencies oscillating more slowly and higher frequencies oscillating more rapidly.

Think of it like a road system for data; lower frequencies, like radio (ranging from about 30 kilohertz to 300 megahertz) and microwaves (300 megahertz to 30 gigahertz), are like old, well-worn highways. They may not be the fastest, but they stretch across vast distances, handling steady traffic over long distances, even through challenging environments.

This makes them ideal for applications like AM and FM radio, satellite communications, and early cellular networks, but the downside is that they have a speed limit – they can only carry so much data at a time.

Wikimedia Commons; U.S. Army

Terahertz waves sit at the edge of infrared light, bridging the gap between electronics and photonics; offering a new frontier for high-speed, light-based data transmission.

Higher frequencies, such as those used in 5G (typically 24 to 100 gigahertz), are like multi-lane freeways in a city. They move much more traffic (data) at higher speeds by packing more information into each wave using techniques that adjust the wave's strength, speed, or timing – known as amplitude, frequency, and phase modulation.

The catch is that these freeways don't extend very far and can't pass through solid obstacles easily, requiring more infrastructure – such as additional cell towers and multiple small antennas – to keep the traffic flowing smoothly.

Terahertz frequencies sit even higher on the spectrum, in a range between microwaves and infrared light. If harnessed effectively, they could serve as ultra-fast express lanes, potentially rivaling fiber-optic speeds without the need for cables.

The challenge, however, has been that these highways have remained unbuilt – terahertz signals are difficult to generate, unstable over distance, and easily disrupted. Now, a discovery using graphene may finally provide a way to construct and stabilize these high-speed roads for wireless data.

Graphene unlocks terahertz

Recent research into 2D materials has shown their potential to revolutionize wireless communication, with MXenes being explored for electromagnetic shielding and interference reduction to improve signal clarity, while other materials, such as transition metal dichalcogenides (TMDs), are being studied for their potential in optical data transmission and nanoelectronics.

While these materials serve different roles, their unique electrical and optical properties highlight the growing functions of 2D materials in advancing communication technologies.

Among these advanced materials, graphene has emerged as a key contender for driving the next evolution of wireless communication, offering a path to harnessing terahertz frequencies.

In a breakthrough that could make this possible, researchers at the University of Ottawa have developed a method to more efficiently convert and control terahertz signals using graphene, solving a major challenge that has prevented this ultra-high-frequency spectrum from being used in real-world communication.

By taking advantage of graphene's unique properties, the researchers designed a device that boosts weak terahertz signals, allowing them to travel more reliably. Previous attempts struggled with signal loss and instability, but this development overcomes those issues by stacking multiple graphene layers, fine-tuning their electrical properties, and placing them on a specially engineered surface to enhance signal strength.

This approach made the terahertz signal more than 30 times stronger than previous methods, moving the technology closer to practical use in next-generation wireless networks, including future 6G systems.

By dramatically improving the strength and stability of terahertz signals, this innovation brings the technology closer to practical use in wireless networks. Stronger terahertz waves could enable ultra-fast, low-latency communication far beyond the capabilities of 5G, supporting innovations like instant data transfer, high-resolution imaging, and advanced security scanning.

"The research marks a significant step forward in improving the efficiency of terahertz frequency converters, a critical aspect for multi-spectral terahertz applications and especially the future of communication systems, like 6G," said Jean-Michel Ménard, Associate Professor of Physics at the University of Ottawa and lead researcher on the study.

While more research is needed to integrate this technology into consumer and industrial applications, this study demonstrates that terahertz communication – once considered impractical – may soon become a reality.