Gabriel Escrig, PhD candidate at the Complutense University of Madrid, has recently been recognized by TalentQ with the prestigious award for the best master’s thesis. His innovative research, focused on Quantum Walks techniques applied to gravitational wave analysis, stood out among the proposals presented for the Quantum Spain program competition. The jury praised both the rigour and originality of his work and the impact of the associated publication, which underscores the enormous potential of quantum computing to solve highly relevant scientific problems.
1. Could you explain, in general terms, what your Master’s Thesis was about?
The study of gravitational waves presents a complex computational challenge, especially in estimating parameters of the astrophysical sources that generate them. Due to the sensitivity of current detectors, we can only detect signals from extremely massive events, such as the merger of black hole or neutron star binaries, although more events are expected to be detected in the coming years. The challenge in parameter estimation is to infer properties such as masses, spins, and distances, which sum up to about 20 parameters. This process relies on Bayesian inference, creating a significant computational bottleneck due to the extensive state space and the high cost of calculating the objective function. This thesis introduces for the first time a quantization of the classical techniques used to develop a quantum Metropolis algorithm, which shows a polynomial advantage in scaling and represents a promising step toward optimizing these processes.
2. What motivated you to choose this particular topic for your master’s thesis?
I had the opportunity to train in the field of gravitational wave astronomy thanks to a research scholarship at the Department of Astronomy and Astrophysics at the University of Valencia. This field was also the basis of my undergraduate thesis in Physics. From my early research, I saw a great interest in accelerating current algorithms for parameter estimation. Initially, we approached this challenge from the perspective of Machine Learning, developing a convolutional neural network capable of performing detection and inferring a reduced number of parameters. However, as I continued my studies in the Master’s program in Theoretical Physics, I decided to explore a more theoretical branch, which led me to investigate how quantum computing could offer new solutions to this challenge.
3. What do you consider to be the main contribution of your work to the field of quantum computing?
Although the field of quantum computing has advanced significantly in recent years, its applications in astrophysics have been limited. I believe it has been very interesting to demonstrate a practical advantage of quantum algorithms over the state-of-the-art classical algorithms and to have taken a small first step that could open the door to future research in gravitational wave astronomy.
4. What were the greatest challenges you faced during your project and how did you overcome them?
There is a significant difference between quantum algorithms in the abstract of a paper and their practical application. Often, algorithms that theoretically promise significant advantages, in practice, require an enormous number of quantum gates. Maintaining the theoretical advantage while dealing with these gates was one of the biggest challenges. However, with dedication and a careful approach, it was possible to optimize the processes through subroutines that improved efficiency.
5. Do you plan to continue researching in this field? Do you have any ideas about where you would like to direct your future projects?
Without a doubt, the intersection between astrophysics and quantum computing is a very promising field with vast potential to explore. Based on the results obtained in the thesis, I have focused much of my doctoral efforts on continuing this research, developing a hybrid computational framework capable of performing the entire parameter estimation process, which has led to two scientific publications. Despite the progress made, the field remains vast, and I would like to continue tackling the challenge of gravitational waves from different perspectives within quantum computing.
6. Do you think that such contests are important for promoting research in quantum computing among students? Why?
Any initiative that supports research among young people is more than welcome, especially considering that they are the most vulnerable in terms of job stability in the research field, due to the limited number of research contracts and the precariousness of some of them. These contests not only provide a platform to showcase their work but also offer a crucial incentive to continue advancing in their careers.
7. What advice would you give to other students interested in starting a career in quantum computing?
The field of quantum computing is constantly evolving, offering a wide range of opportunities. It is a multidisciplinary area encompassing a diverse array of possibilities, so regardless of whether you come from a technical or theoretical background, there is a place for you. Additionally, it is a relatively young field with much to discover, ensuring a dynamic and stimulating environment.
8. How do you see the state of quantum computing in Spain? What do you think could be done to promote research in this field?
Spain has excellent scientists and professionals in the field of quantum computing, both in academia and in international companies. The field is still in a consolidation phase, and as more results are obtained, its impact will increase, leading to a rise in the number of chairs and companies in the sector. Given the rapid technological development in this field, it seems crucial to foster collaborations between universities, research centers, and companies. Initiatives that strengthen the connection between academia and industry could facilitate the transition from theoretical research to practical applications, thus promoting the advancement of quantum computing in Spain.
