Computer systems are an essential part of each field of life today. With years advancing and the world getting ‘smarter’ daily with technologies like the Internet of Things (IoT), Machine Learning, and Artificial Intelligence (ML and AI), the need for computational power and performance has continuously increased. If we look at this increasing need for computational power from a hardware perspective, all the advances in hardware performances were governed by Moore’s Law until recently. This law has been guiding the advances in computing systems – from the device, circuit, and architecture level of the conventional Complementary Metal Oxide Semiconductor (CMOS) technology-based hardware for almost five decades, which has been solely answering ever-increasing demands of computational needs until recently. However, CMOS technology has reached its scaling and performance limits; it has become crucial now to find alternatives to CMOS technology, and many alternative technologies are being studied and investigated. Single Flux Quantum (SFQ) is one of the potential technologies of the future.

The key characteristic of this technology is its ultra-high switching speed and ultra-low energy required for switching. Based on the literature available when writing, SFQ systems demonstrated several 10~100GHz operation frequencies with translates an order of magnitude or two more than the state of the art of CMOS technology. Due to its superconducting nature, SFQ circuits need refrigeration and shielding equipment. However, their power consumption and cooling costs are slightly better than corresponding SFQ systems.

The refrigeration requirement of SFQ systems cannot be applied in portable and handheld embedded applications; however, because of their ultra-high speed, these superconducting circuits are still attractive in high-performance computing (HPC), i.e., supercomputer or data center, in pursuit of high computing speed and low power consumption.