High-speed graphene-based sub-terahertz receivers enabling wireless communications for 6G and beyond

Wireless data traffic has grown at an unprecedented rate, creating an urgent need for innovative solutions to overcome current technological limitations. Sub-terahertz (sub-THz) carrier frequencies offer increased capacity and low attenuation for short-range wireless applications. Here, we demonstrate sub-THz receivers based on graphene, which offer several advantages over state-of-the-art sub-THz receivers, such as a direct detection scheme, passive operation, and compactness. We exploit multiple concepts incorporated into a single device, including a high-quality sub-THz cavity placed in the vicinity of a high-mobility graphene channel to overcome its intrinsically low absorption. The graphene receivers achieve a multigigabit-per-second data rate with a maximum distance of  ~ 3 m from the transmitter. We demonstrate a trade-off between bandwidth and responsivity: a setup-limited 40 GHz bandwidth in low-responsivity devices, and a maximum responsivity of 0.16 A/W in devices with a 2 GHz bandwidth. Our findings enable applications such as chip-to-chip communication and close-proximity device-to-device communication.