Scaled Production of High Density Cryogenic FLexible coAXial (FLAX) RF Ribbon Cables

High-density cryogenic wiring is a critical component for gate-based quantum computers, quantum annealing devices, superconducting supercomputers, transition edge sensors, Microwave Kinetic Inductance Detectors, nanowire single photon detectors, and a wide range of other applications. Quantum computers will be as important to the next hundred years of technology as the internet, integrated circuit, or radio receiver have been to the last 100 years; by relying on properties of quantum mechanics, they will solve problems in seconds that the most powerful classical supercomputers in the world could work on for generations and never scratch their surface. This reinvention of computing will lead to a new era of personalized medicine, clean and effectively unlimited power, a deeper understanding of our universe, and a transformed civilization. Quantum will also require the development of a new supply chain that moves technologies out of laboratories and into scaled commercial use. While some of these technologies are obviously complex, such as sub-kelvin cryogenics, single-photon emitters, lasers, and low-temperature electronics, even seemingly straightforward elements of a quantum system, such as wiring, are subject to a global supply pinch and in need of significant innovation to meet the world’s growing demand. The wires used in superconducting systems are typically a major factor in total system cost and an obstacle to scaling up system performance. Moreover, today they can only be commercially sourced from international suppliers such as CoaxCo (Japan), Delft Circuits (Netherlands), or any of a number of Chinese suppliers. Existing solutions are lower density than optimal, leading to practical limits on the number of qubits that can be installed in commercially available cryogenic systems, and exorbitantly expensive -- an individual wire for a quantum system can easily cost upwards of $1,200, meaning that wiring a powerful gate-based quantum computer using existing wiring solutions costs over $250k. Moreover, lead times on delivery of these wires are typically at least several months as these low-scale products are painstakingly manufactured overseas. The novel FLexible coAXial (FLAX) cables to be produced as a result of this proposal create a new type of high-density data cable for superconducting electronics applications which have high density, low attenuation, low crosstalk, and low heat load. It builds on the outstanding performance achieved by UCSB in small-scale production and leverages established manufacturing technologies to scale and economize production.