Efficient Superconductor Arithmetic Logic Unit for Ultra-Fast Computing

Abstract: We present a 4-bit Arithmetic Logic Unit (ALU) utilizing superconductor technology. The ALU serves as the central processing unit of a processor, performing crucial arithmetic and logical operations. We have adopted a bit-parallel architecture to ensure an efficient and streamlined design with minimal fanin/fanout and optimal latency. In terms of fabrication, the ALU has been fabricated using a standard commercial process. It operates at an impressive clock frequency exceeding 30 GHz while consuming a mere 4.75 mW of power, including applied reverse current, encompassing static and dynamic components. The ALU contains over 9000 Josephson junctions, with approximately 7000 JJs dedicated to wiring, delay lines, and path balancing, and it has over 18% bias margin. Designed as a co-processor, this arithmetic logic unit will work with external CMOS memory and processors via interface circuits. Thorough testing and validation of the ALU's functionality have been conducted with digital and analog simulations, and all the components were fabricated and measured within a 4K pulse-tube cryocooler. Experimental verification has confirmed the successful operation of both the arithmetic and logic units. These results have been analyzed and are presented alongside the experimental data to provide comprehensive insights into the ALU's behavior and capabilities.