Some of the most fundamental and intriguing phenomena occurring in nature, ranging from the interaction of elementary particles to conventional and exotic matter, are described by gauge theories. The study and understanding of such phenomena in most cases is only possible by means of numerical simulations as analytical solutions are not available. These numerical simulations are one of the most complex challenges that physicists have undertaken in the last decades, attacking the problem mostly by means of Monte Carlo methods. Unfortunately, despite the enormous efforts performed and the successes achieved, many significant physical phenomena remain beyond the field of applicability of Monte Carlo methods due to a fundamental limitation, the sign problem.
As R.Feynman already pointed out when he first proposed the idea of a quantum computer, fully developed quantum technologies will be extremely effective to attack the problems currently out of reach. The goal of the QTFLAG project is to make significant two steps along this path: the first one is to develop classical simulation methods inspired by quantum information science (tensor network methods) that do not suffer from the sign problem. The second step is to develop and run quantum software on quantum simulation platforms such as trapped ions or cold atoms in optical lattices, that is, to replace classical numerical simulations with experiments where a quantum system in the lab mimics the physics of the lattice gauge theory of interest, allowing its study in a controlled environment.
QTFLAG will exploit the knowledge from experimental and theoretical quantum optics; atomic, molecular and optical physics; quantum information science; high energy physics and condensed matter. Its results will potentially impact different fundamental and applied fields of science ranging from materials science and quantum chemistry to astrophysics. From the technological point of view, among many different potential applications, the results of this project will enable, in the long run, the study and design of novel materials with topological error correcting capabilities, which will play a central role in the quest for building future quantum computers.
QTFLAG is funded within the QuantERA ERA-NET Cofund in Quantum Technologies.
The Paul trap setup used to perform a proof of principle quantum simulation of a lattice gauge theory.