Can we build classical control circuits for silicon quantum computers? 2nd Workshop on Non-Silicon Computation

Abstract

Many who propose quantum computing technologies focus on the quantum datapath without addressing the complexity of the classical control. We investigate the complexity of control for a specific technology, namely the Kane silicon quantum computer. We show that the pulse sequences required to effect one of the simplest operations – two-bit swap – poses a significant challenge to scalable implementation. The reason for this is two-fold: first, extremely cold operating temperatures require use of something other than CMOS for control and, second, pulse-generation for a single bit in the datapath requires many classical transistors. The result suggests that architects must focus on a form of SIMD for quantum datapaths, sharing pulse-generation circuits between as many quantum bits as possible. 1