Quantum computers promise capabilities far beyond those of today’s classical machines, with potential applications in areas such as materials discovery, secure communication, and advanced sensing. However, existing quantum processors face major engineering barriers to continued progress. Present day superconducting quantum processors are built as single, monolithic chips in which all quantum bits (qubits) reside on a single substrate. As systems grow, this architecture becomes increasingly fragile: crosstalk rises, wiring becomes unmanageable, and a single faulty component can compromise the entire processor. As a result, the monolithic approach cannot be scaled to the chip sizes or wiring densities required for future fault-tolerant machines. A promising alternative is a modular architecture in which many smaller, high quality quantum chips are interconnected to create a larger and more capable system. Realizing such modular systems requires new technologies for routing extremely weak microwave signals between chips without disturbing their delicate quantum states. This CAREER project will develop such a technology using a hybrid superconductor–semiconductor component known as the Josephson Junction Field Effect Transistor (JJFET). The JJFET marries the low loss, coherence preserving properties of superconductors with the voltage tunable control and nanoscale footprint of semiconductor transistors, enabling compact, efficient, and reconfigurable routers that can connect quantum chips on demand. Success in this project will provide a key architectural building block for scaling up future quantum computers. In parallel, the project integrates hands on training for graduate, undergraduate, and K–12 students, strengthening the nation’s quantum ready STEM workforce and broadening public engagement with emerging quantum technologies. Technically, the project will establish JJFETs as voltage controlled superconducting elements capable of routing single photon microwave