Exploiting first-generation quantum computers

Context: Prof Benjamin's group (qtechtheory.org) has an ongoing theory project which uses a combination of analytic techniques together with conventional supercomputers to predict the behaviour of 1st generation quantum computers including their limitations and flaws. The aim is to find applications for these powerful but imperfect systems. Many research groups around the world are getting close to realizing the first generation of a profoundly powerful new class of technology: quantum computers. Building such a machine means learning to control qubits (quantum bits). Different approaches are being tried: qubits may be individual atoms, or nanostructures in diamond, or superconducting loops. But all have one thing in common: the control we can achieve is far lower than the control we have over bits in conventional computers. The first generation of quantum computers will therefore be imperfect, by comparison to our reliable conventional technologies, but they will still have the potentially to be vastly more powerful.

This theory project will use both analytic techniques and conventional supercomputers to understand the behaviour of 1st generation quantum computers including their limitations and flaws. The primary goals of the project will be to identify applications, such as novel materials and chemistry discovery, which may be able to run successfully on a near-term quantum computer despite its imperfections. As a natural complement to this, when a study results in the conclusion that a specific class of problems are unlikely to be accelerated by quantum computers, then this is also a valuable outcome to be reported. It is also a potential theme of interest to obtain useful measures of the power of emerging quantum devices; the metric called "quantum volume" introduced by IBM is one such example but for various reasons it is desirable to have a plurality of benchmarks.

The research will include both analytic "pen and paper" theory as well as numerical modelling using conventional computers to simulate quantum machines; for the latter goal the group has the QuEST family of software packages that allow efficient simulation to the extent possible. As increasingly useful quantum prototype hardware becomes available online, it is likely that these systems (which have hitherto been too small and imperfect to be useful) will also be used.

Resources available to the project include the Oxford ARC (Advanced Research Computing) facility and specifically the ~£1M cluster of compute and GPU nodes that have been acquired as part of the NQIT hub and will be acquired as part of the new Hub in Quantum Computing and Simulation. Primary support will come from Prof. Simon Benjamin (Oxford) and the host group includes 14 individuals working in related areas including postdoc Dr Balint Koczor at Oxford.

This project falls under the EPSRC category "quantum technologies".