While the billion-dollar question is about when quantum computing will become commercially viable, among the problems being tackled at the moment is how to make the most of current technology, where quantum devices experience a high error rate.
Although the industry can produce machines with hundreds of physical qubits, the actual number of logical, error-free qubits available in the latest quantum computers remains very small.
As the technology improves, researchers are investigating how to get the best out of today’s noisy quantum computers and considering the types of problems that quantum devices with large numbers of logical qubits could solve.
Simulations for drug discovery
Lucy Robson is a quantum algorithm scientist at Universal Quantum. She is part of a team looking at how quantum computing could be applied in drug discovery.
Speaking to Computer Weekly about her work, Robson says: “Our focus is not just about looking at quantum algorithms, which can implement real-world use cases, but it’s also about understanding how we can build high-performance quantum error correction, and in particular, how we can get advantages for Universal Quantum’s scalable trapped ion quantum computing hardware through clever design of error correction protocols.”
Considering the challenges of quantum simulations for drug discovery, Robson says a large-scale fault-tolerant quantum computer is needed: “This is something which is many orders of magnitude larger than the hardware that we currently have at the moment.
“We’re talking about needing hundreds of thousands or millions of qubits to be able to support the overhead of quantum error correction at the scale that we would need to execute very large algorithms, and what we’re seeing broadly is a real push to try to understand how far away we are from fault tolerant quantum computing.”
Robson says this problem is not solely a hardware issue. “It is also about considering what application developers need – the middleware and software tools that will be needed for people who are domain experts in computational chemistry to be able to make use of these quantum devices themselves,” she adds.
Rather than a treating a quantum computer as an esoteric and specialised device that can only be operated by people with a very specific skill set, Robson hopes such tooling will open up quantum computing to software engineers who are not experts in quantum computing.
Robson’s work is currently focused on a specific use case for quantum computing that looks at how quantum algorithms can accelerate the simulation of chemical properties – specifically, quantum chemistry for the drug discovery process.
Last year, Universal Quantum announced it was collaborating with the Open Quantum Institute (OQI) on using quantum computing in drug discovery. The team has been investigating how quantum simulations might accelerate the discovery of novel, non-hormonal treatments for endometriosis, a disabling and progressive condition that affects around 10% of women globally.
According to Robson, the average time to diagnosis in the UK is between seven and 10 years: “This is really symptomatic of systemic underfunding for women’s health in general. While we originally started out on quantum algorithms, one of the great use cases for this is simulation of physical systems and quantum chemistry, and one of the main applications of quantum chemistry is in pharmaceuticals and drug discovery.”
Understanding quantum
For people who have not encountered quantum mechanics – the phenomenon that enables quantum computers to run computation beyond the realms of the most powerful supercomputers – the concepts it embodies such as superposition are mindboggling. “It’s certainly counterintuitive,” Robson adds.
She recalls the advice Nobel laureate and physicist Roger Penrose gave in the foreword of a book she was reading about learning difficult concepts: “I remember picking up one of his books when I was about 16 years old, just about to start A-level maths, so I was quite unfamiliar with a lot of the notation and the terminology that was being used.
“In the short time that I’ve been involved in the field, I’ve seen things I had read about as a theory paper now being published experimentally”
Lucy Robson, Universal Quantum
“His advice for dealing with any sort of new or strange formula that you haven’t seen before is to try to get an intuitive understanding. That may not be about reading the equation or understanding the terminology, but reading a description, looking at a diagram and trying to get some concept in your mind of what this thing is actually trying to describe, and then go back and learn the notation and learn the formula.”
She says this approach has always served her well: “It is a thing that I always do when I find something new and unfamiliar.”
Her advice to software developers who want to get into quantum algorithms is to understand linear algebra: “Many of the concepts seem strange and alien. But I had the benefit of coming from a degree where we did a lot of linear algebra, so I would argue that one of the strongest prerequisites that you do need for quantum algorithms, in particular, is to feel comfortable with linear algebra.”
Robson’s journey to quantum computer began when she started exploring the subject. “There was this wealth of new material that was available, so I started trying to understand what on Earth is quantum, and I discovered that there’s an enormous crossover between quantum computing and theoretical computer science. That’s really what really got me hooked,” she says, recalling her experience as a self-taught programmer, reading RFCs (request for comments), and her work in cyber security after studying computer science.
Robson then had the opportunity to work on a small scale project looking at applications of quantum computing for the defence sector.
Robson is confident the technology will eventually work commercially. “In the short time that I’ve been involved in the field, I’ve seen things I had read about as a theory paper now being published experimentally,” she says, adding that this shows how much has been achieved in the past decade.
Specifically, Robson says she is extremely pleased to see there is now sustained long-term investment coming from the UK government. The company she works for, Universal Quantum, was spun out of Sussex university and received a grant of £7.5m as part of Innovate UK’s Strategy Challenge Fund in 2021.
“In the UK, we have a phenomenal National Quantum Technologies programme,” she adds, pointing out that progress is being made not only on quantum computing hardware but also software and tooling. “One of the things that’s quite encouraging for me is seeing how the ecosystem is growing at pace alongside the developments in hardware and theory.”
Listen to the podcast with Lucy Robson here >>