NbN-Gated GaN Transistor Technology for Applications in Quantum Computing Systems

A NbN-gated AlGaN/GaN high electron mobility transistor (HEMT) technology for applications in quantum computing systems is demonstrated for the first time. Transistors with gate lengths scaled to 250 nm were characterized at 4.2 K, with excellent gate modulation (I
D,ON
/I
D,OFF
~ 10
⁸
) and current saturation. The potential of these devices for low noise amplifiers was evaluated, revealing a low DC power dissipation of 25 μW/μm when biased for expected minimum noise. The RF performance was also characterized at 4.2 K. This work highlights the potential of NbN-gated GaN transistor technology for applications in low-noise cryogenic amplifiers in future quantum computing systems.