Quantum computing and HPC: trials and tribulations
20 August 2026
EPCC Chancellor's Fellow Oliver Brown writes about the talk which he recently gave at the Quantum-HPC Community Building Workshop.
Figure 1: Two possible extremes of quantum HPC.
I believe that the quantum computing journey, especially in scientific computing, begins with honest conversations. As such, I wanted to begin the day by talking about something that’s been on my mind a lot lately: is quantum HPC even achievable?
There are broadly two ways quantum and classical computing may interact in the future, as illustrated in Figure 1 above: quantum and classical may be tightly intertwined, with Quantum Processing Units (QPUs) working as accelerators, or a quantum computer may be a large scale facility unto itself with only a loose coupling to classical HPC.
We could end up with only one of these models succeeding, or both.
A lot depends on how small the hardware ends up being – speaking generally, smaller devices require less power, and so produce less heat, which means they can be more tightly coupled to other things. I cannot say with any certainty that the model on the left of Figure 1 is viable, although I believe it will be. In fact, I believe that one day we will see both these forms of hybrid quantum-HPC being used for quite different applications. What I can, and often do, say however is that we plan to ensure that the software ecosystem for scientific computing is ready to take advantage of quantum computing and HPC, whatever that ends up looking like.
After opening my talk with some of the challenges facing hybrid quantum HPC, I laid down a challenge to the other speakers – could they convince the audience that it was worth investigating? A challenge they rose to admirably!
It was great to be a part of the day, and I enjoyed chatting to members of the computational science community about both the challenges of bringing together quantum computing and HPC, and the opportunities it may bring.
Many thanks to Omer Rathore and John Masih (NFCS+ Programme Manager) for organising the event, for inviting me to kick the day off with my musings on the nature of HPC, and for doing their best to alleviate the London heatwave! I’ve asked Omer if the next one can be held a bit further North…
This workshop was sponsored and organised by NFCS+ and organised by Omer Rathore.
National Federated Compute Services NetworkPlus
EPCC involvement with NFCS+ includes the projects Research Data Landscape Survey, Federated IAM for Existing Infrastructures, Tokenised Authentication for Research Computing Services, and Federated Data Movement.
