An optimization of traditional CPU emulation techniques for execution on a quantum computer

Abstract

The use and adoption of quantum computers by the wider computing community has been impeded by the need to adopt new programming techniques. These techniques involve moving from a high-level language where the programmer can define and manipulate objects, to a quantum model where the programmer defines and configures the circuits at a gate level. A jump too far for many. Previous work by the authors aimed to ease this transition through the use of a software development kit (Qx86 SDK) that emulates a traditional CPU for execution on a quantum computer which focused on delivering the capability. This paper now presents a number of new methods that extends and improves the SDKs capability. These methods include optimizing traditional logic gate emulation, multiple gate simplification methods, reducing the number of required qubits, and alternative optimized techniques for many CPU instructions. A quantum machine code mapping method is also described to propose the emulation of a traditional/quantum hybrid CPU prototype. Whilst still orders of magnitude slower than the performance of a traditional CPU in terms of arithmetic, logic and bitwise operations, execution speed is shown to be markedly improved (in some cases by more than 1,000%) and without introducing any unrealistic requirements (that is, all execution can be performed utilizing less than 32 qubits). The usefulness of the SDK has now been enhanced as a reference guide, where the programmer/researcher can contrast traditional methods vs multiple quantum methods of execution.