Dynamic Metasurfaces for Multiplexed Control of Superconducting Qubits

Scaling superconducting quantum processors to large qubit counts faces challenges in control signal delivery, thermal management, and hardware complexity. We propose a space-time modulated Josephson Junction (JJ) metasurface architecture to generate and multiplex microwave control signals directly at millikelvin temperatures. Theoretical and numerical results show the generation of multiple frequency tones with controlled parameters, enabling efficient, scalable qubit control while minimising heat loads and wiring complexity. We derive the nonlinear wave equation governing the system, simulate beam steering and frequency conversion, and discuss experimental feasibility.