Finland connects a quantum computer to a supercomputer

Finnish research and technology organisation VTT last month announced a milestone when, in collaboration with CSC – IT Center for Science and Aalto University, it connected the quantum computer HELMI with the pan-European supercomputer LUM. 

HELMI is Finland’s first quantum computer, a 5-qubit system that became operational in 2021. And the system it was connected to is no ordinary supercomputer – LUMI, the fastest supercomputer in Europe, which is able to carry out 309 petaflops. Like HELMI, LUMI became operational in 2021.  

Hosted by CSC – IT Center for Science, LUMI ranks third in the latest Top 500 list of the world’s fastest supercomputers. Not only is it fast, but it is also eco-friendly (relative to other supercomputers), ranking seventh in the Green 500 list of the most energy-efficient supercomputers in the world.

A practical reason for making a hybrid system like this is that quantum computers are difficult to use as standalone systems. Programmers have to take into account the unique architecture of any given system and the nature of the errors observed for each of the qubits on it. Every qubit is faulty in its own unique way.

On top of that, the ecosystem around quantum computing is not mature enough to offer a good set of tools to program quantum computers, to execute programs and to read the output. But there are other reasons. 

“We aim to augment supercomputing with quantum computing,” said Ville Kotovirta, leader of the quantum algorithms team at VTT. “The most challenging problems for classical computing – for example, electronic structure problems – could hopefully be solved more efficiently with quantum computers in the future. On the other hand, supercomputers could help optimise quantum algorithms and they can post process measurement data to mitigate errors in the computation. As quantum computers get larger, these optimisation problems get more challenging and could benefit from supercomputing.”  

Kotovirta added: “Researchers can start developing and studying new hybrid algorithms that take advantage of both quantum and classical computing. This is not trivial and requires thorough understanding of the problem and formulation of new algorithms to divide computational tasks into quantum and classical parts optimally.”

The recent move to connect HELMI to LUMI was carried out to support researchers in the short term. But even after quantum computers become industrial, connecting them to traditional computers will still make sense. One future scenario is to provide supercomputing services to businesses, where the supercomputer solves most of the problems but then allocates to a connected quantum computer a subset of tasks for which there is a quantum advantage. 

Experts agree that one day, quantum computers will solve a very small set of useful problems that supercomputers would take thousands of years to solve – and they will solve those problems in minutes or hours. Such problems include developing new products and materials for the pharmaceutical, chemical and battery industries.

Machine learning applications for generating novel molecular structures based on existing molecular data could be faster and more accurate, speeding up significantly the process of new material design. Quantum algorithms will also be very good at solving optimisation problems – for example, finding the best design for a supply chain, finding the best travel route, or figuring out the optimal asset allocation for a financial portfolio. 

Mikael Johansson, quantum strategist at CSC, believes another advantage of connecting the computers is that it brings experts together – and a good place for different experts to sit down and talk is at the centres hosting high-performance computing (HPC).  

“Reaching quantum advantage is a truly multidisciplinary problem, regardless of whether you measure advantage as time-to-solution or energy consumption-to-solution,” said Johansson. “Solving the problem requires crosstalk between several disciplines. Otherwise, crucial points of view and potential pitfalls will be overlooked when setting up the supercomputer and quantum computer infrastructure.

“A joint effort by HPC and computer science wizards, quantum computer hardware and software professionals, AI [artificial intelligence] gurus and domain experts of the specific modelling problem is required. Only then can the unruly, noisy, imperfect quantum computers be tamed and put to productive work.”

VTT Technical Research Centre of Finland worked with CSC and Aalto University, within the framework of the Finnish Quantum Computing Infrastructure to make the connection between the computers.   

“The connection uses the secure HTTPS protocol between the endpoints,” said Kotovirta. “Users develop a hybrid algorithm on the LUMI side and submit the job to the LUMI queuing system for execution. Quantum jobs are forwarded to HELMI securely over HTTPS and the HELMI back end controls the hardware electronics to do the actual quantum computation. The result is returned to the LUMI side to the program that made the call. The program might then combine the result with whatever classical computation it may have performed. Then it might start the next iteration, or it might display the results to the user." 

Johansson added: “By integrating supercomputing, world-leading AI capacity and quantum acceleration, we have pooled all the necessary components for the upcoming quantum revolution in computing. Now we need to get them working together, seamlessly and efficiently. This is no trivial task, and work needs to start immediately in order for the machinery to be in place when the truly powerful quantum computers come to market.”

The connection between HELMI and LUMI is a major milestone on the road towards industrial-grade quantum computing in Finland. Two other major milestone are in the works – VTT is currently developing a 20-qubit quantum computer, and already has plans to upgrade to 50 qubits in 2024. 

Finland is now one of the few countries in the world to have connected a quantum computer and a supercomputer – and the first in Europe. Users from Finnish universities and research organisations will now be granted access to the new infrastructure to experiment with quantum computing.