An international team led by researchers from the Institute of Corpuscular Physics (IFIC), located in the scientific-academic area of the Science Park at the University of Valencia and joint center of the Higher Council for Scientific Research (CSIC), has developed an algorithm that allows for more accurate prediction of the behaviour of elementary particles in accelerations such as CERN’s Large Hadron Collider (LHC). This new method is based on quantum vacuum fluctuations, a phenomenon in physics that provides more accurate mathematical representations of physical processes. This method, published in the prestigious scientific journal Physical Review Letters, has been implemented for the first time on a quantum computer, an advance reported in another article published in the journal Quantum Science and Technology.
The void of quantum physics is a fascinating concept, but at the same time disconcerting. This represents a dynamic scenario where particles and antiparticles arise and annihilate each other constantly, guided through the Heisenberg uncertainty principle. Despite their short duration, quantum vacuum fluctuations leave an indelible mark that significantly improves theoretical predictions about the behaviour of subatomic particles, which is vital for interpreting data in experiments such as the LHC.
The theoretical models that predict this behaviour have traditionally been based on the diagrams of Nobel prize winner Richard Feynman. Graphically and concisely, these models represent the interaction between a set of particles that initially collide and those that emerge as a result of such collision. However, the mathematical formalism used sometimes allows the production of some of these particles with exactly zero energy or in the same direction.
Although these configurations are mathematically valid, they have no physical significance. This phenomenon reflects an essential characteristic of quantum mechanics: the number of particles is not fixed and can change due to quantum fluctuations. This complicates theoretical calculations and creates great challenges, as often infinite mathematical problems arise that make it difficult to obtain accurate results.
As explained by Germán Rodrigo, principal investigator of the LHCPHENO group at the IFIC leading the work, when a mathematical formalism leads to necessary complications, "it is usually a sign that there is a more elegant and direct way to obtain the result". "The method we have developed clearly incorporates the fundamental physical principle of causality, or cause and effect. In addition to enabling more advanced theoretical predictions, it offers a new perspective for understanding the enigmatic quantum properties of vacuum", says the CSIC physicist.
In this way, the research led by IFIC proposes an innovative approach: to base theoretical calculations on vacuum amplitudes, that is, diagrams which do not include external particles and focus on intrinsic fluctuations of quantum vacuum. This strategy removes the difficulties associated with infinite values and provides more accurate mathematical representations of real physical processes.
The research led by IFIC proposes an innovative approach: to base theoretical calculations on vacuum amplitudes, that is, diagrams which do not include external particles and focus on intrinsic fluctuations of quantum vacuum
Applications in quantum computing
The absence of infinities, together with the intrinsic quantum nature of particle physics, has allowed researchers to successfully implement their new algorithm in a quantum computer. For the first time on this type of platform, this milestone has facilitated the prediction of the decay rate of the Higgs boson, the elementary particle responsible for mass in the universe, second order of quantum field theory, the theoretical framework combining quantum mechanics and special relativity to describe how elementary particles interact.
This represents a significant advance, because calculations at high orders in quantum field theory, where each new order significantly improves the description of the system, are extremely complex and require great computational capacity. Achieve this result in a quantum computer, and validate its ability to address advanced theoretical physics problems; opens up new possibilities for the use of quantum computing in elementary particle simulations and other applications in high-energy physics.
Jorge Martínez de Lejarza, PhD student at the IFIC and one of the authors of the latest work, points out: "Quantum computers promise to revolutionize computing in the 21st century, surpassing classical computers in solving certain specific problems. In particle physics we face some of the greatest challenges in science and, in that sense, our mission is to reformulate them to allow their execution in quantum computers, thus contributing to advance a better understanding of the universe".
"Quantum computers promise to revolutionize computing in the 21st century, surpassing classical computers in solving certain specific problems", Jorge Martínez de Lejarza, PhD student at IFIC and one of the authors of the paper
This breakthrough opens up new opportunities for the development of applications in quantum computing and represents a significant step in exploring the frontiers of particle physics. The two studies were carried out in collaboration with research staff from the University of Salamanca, the Autonomous University of Sinaloa (Mexico) and the CERN Initiative on Quantum Technologies.
Source: Communication CSIC Comunitat Valenciana