András Gilyén is sharing ideas and perspectives about quantum simulation, which could achieve results beyond the reach of classical computers within a decade.
It attracted attention well beyond professional circles when András Gilyén and his internationally renowned team of American and European researchers became finalist in the global competition XPRIZE Quantum Applications. The jury selected them from 133 teams representing 31 countries. The group – which also includes several researchers from the HUN-REN Wigner Research Centre for Physics – is currently working on its final submission due in November, while receiving professional guidance from the judging panel that selected them. (The XPRIZE finalist team Gibbs Samplers is presented in this video by team leader András Gilyén – ed.)
Although final results will only be announced in spring 2027, András continues to lead several major research projects. His 2025 ERC Starting Grant on “Genuine Quantum Algorithms Inspired by Thermodynamics and Natural Phenomena"
became the 13th ERC project at Alfréd Rényi Institute of Mathematics, while his successful Lendület (Momentum) Grant supports his work as head of MTA–HUN-REN RI Momentum Quantum Computing Research Group, focusing on “Quantum Generalizations of Markov Chains Monte Carlo Methods (MCMC).”
At the end of April, he gave a professional lecture on applications of quantum algorithms at the meeting of the Quantum Technology and Supercomputer Platform (QSCP) held at the Budapest headquarters of IBM. Earlier, on April 9, he was one of the plenary speakers at the scientific programme “Science Event Celebrating 10 years of QuSoft,” addressing a professional and business audience interested in quantum research. The event showcased a decade of achievements in quantum software research and described András Gilyén as follows: András Gilyén is a researcher in quantum computing known for developing important quantum algorithmic techniques. His work serves as a versatile building block for many modern quantum algorithms. He has made significant contributions to improving the efficiency of quantum computers in solving complex problems — advances that are central to the development of next-generation quantum software.
| András Gilyén, whose research focuses on quantum computing and algorithm theory, is 37 years old. He earned his PhD in 2019 from the University of Amsterdam in the theory of quantum computer algorithms. “As a PhD student, I essentially grew up scientifically together with QuSoft, the now internationally recognized research center for quantum software and technology,” he recalls. (QuSoft was founded in 2015 by the CWI, i. e. the Dutch National Research Institute for Mathematics and Computer Science and the University of Amsterdam, and has since achieved outstanding results in quantum computing and quantum information science, ed.). From 2019 onward, he spent two years as a postdoctoral researcher at California Institute of Technology (Caltech). |
“We are living in the heroic age of quantum computers. It is similar to the early era of classical computers in the 1950s, when machines filled entire rooms and only a handful of experts had access to them. At that time, only a few specific problems could be studied with them. Today, quantum computers are still similarly distant from industrial users or everyday people. Building quantum computers is still largely fundamental (discovery) research, though we are no longer at the very beginning. A reliably functioning prototype may still be five to ten years away,” summarizes András Gilyén, research fellow at the Department of Probability and Statistics of Rényi Institute.
“As a result, there is growing interest from both decision-makers and society regarding what kinds of applications may become feasible and when. This is what I try to illustrate in my talks, including recently at the QSCP meeting,” he continues.“And from my perspective, observing the rapid development of my field, it is realistic that within 5 –10 years quantum simulation will already tackle practically relevant problems that humanity cannot currently solve with any classical computer. After that, within roughly 10 –15 years, I expect breakthroughs in cryptography through quantum computers, potentially enabling the cracking of encryption methods widely used today. This may seem negative at first glance from a civilian perspective, though it is of obvious importance for intelligence agencies and security experts. Beyond that, in 15 – 20 years, even broader applications may emerge. Fifty years from now, quantum technologies could become useful for many optimization tasks, provided technological development reaches a level where such applications become part of everyday life.”
We may eventually reach the point where quantum computers are used across virtually every area of life to solve large-scale, highly complex, and computationally demanding optimization problems. When asked about concrete applications, András explains:
“There are many algorithms that approximate difficult computations through random sampling. The more samples we take, the more accurate the result becomes. Quantum computers can drastically reduce the number of required trials: from a million to just a few thousand. On a larger scale, this could mean reducing calculations from a trillion samples to just a few million, which is an enormous difference. Within a few decades, we expect this effect to become exploitable, primarily in pharmaceuticals and materials science, where one needs to identify molecules or lattice structures with specific desired properties.”
| In physics, the word quantum refers to the smallest possible unit in which a physical quantity can occur. Nature does not appear continuously, but rather in small “packets.” Light, for example, behaves both as a wave and as tiny packets of energy called photons, which always appear in whole units. (A “half photon” does not exist.) Energy is exchanged not in arbitrary amounts, but in discrete units – these units are quanta. Quantum mechanics provides the theoretical foundation for quantum computers, which process information using the laws of quantum physics instead of classical bits. Building such machines remains a major technological challenge today.The true advantage of quantum computers lies in enabling entirely new kinds of operations able to solve certain problems far more efficiently. The transition from classical to quantum computing may therefore represent a fundamentally deeper technological leap forward. |
“It is still difficult to foresee what will happen within fifty years, just as people in the 1950s vastly underestimated the eventual applications of classical computers. Their true usefulness became clear only over time, and we expect the same with quantum computers. Quantum simulation may already produce results within a decade that are unattainable with classical computers, potentially leading to breakthroughs in materials science and later quantum chemistry,” says the Rényi researcher, emphasizing both the possibilities and the limitations. His team, Gibbs Samplers, is actually developing an advanced quantum simulation method that may also prove useful for optimization tasks. Their goal is to create an algorithm for materials scientists that could be used in material modeling, potentially saving enormous amounts of costly experimental testing before arriving at a material with ideal properties.
Gilyén adds that quantum computers may prove especially effective in understanding materials with lattice-like spatial structures. This is particularly exciting in the case of superconductors, which are crucial for generating powerful electromagnets used in fusion power plants or magnetic levitation trains. The challenge is that superconductivity currently only occurs at extremely low temperatures. Even so-called high-temperature superconductors are still far too cold for humans.
Researchers hope that improved quantum simulations of simplified material models may lead to a better understanding of high-temperature superconductivity or perhaps even to the discovery of superconductors operating closer to room temperature, if such materials exist at all. Quantum simulation could become a powerful tool in this quest.
This kind of research is, in fact, classical exploratory science, much like the revolutionary impact of the scanning electron microscope, which enabled scientists to observe material structures in unprecedented detail and thereby paved the way for countless applications. Quantum computing may become a similarly transformative tool, opening entirely new scientific and technological possibilities.
“I am researching the technology of the future – something already on the threshold of tangible realization, but not yet usable today because the hardware is still insufficient. We hope that within 5–10 years it will be. We are literally pushing the boundaries of human knowledge, as is typical in frontier science. At present, we cannot yet test many of the ideas we develop because the technology is not ready. But there are strong reasons to believe in the broad future applications of quantum technologies, and a true technological breakthrough is entirely possible.”
It is no coincidence that the finalists of the three-year, Google-sponsored competition, with a total prize pool of five million dollars, are all developing new or improved algorithms aimed at bringing practical quantum applications closer to reality.
In summary, quantum computers are expected to become indispensable for solving certain highly specialized computational problems in the future. At the same time, building reliable quantum computers remains an enormous challenge. Many of their most important applications will likely emerge alongside the technology itself – much as no one could fully foresee the transformative impact of classical computers during their own pioneering era.