Detail Project and Funding

Abstract: Our understanding of the physical world, from cosmological distances to subatomic scales, is based on
field theories, with General Relativity and the Standard Model among the most validated descriptions of
reality. Despite their history of success, the application of field theories, particularly in the quantum
domain, is still characterized by a rich set of open questions related to processes in- and out-ofequilibrium.

A paradigmatic example of a process in which field theories are successfully applied is that of first-order
phase transitions. In this case, the dynamics of a system far from equilibrium cannot be simply described in
terms of a perturbation of a steady state, but instead require combined tools and concepts from statistical
and quantum mechanics. The transition results from the dynamics between field values associated with
local minima of the system’s energy. In the quantum regime, these local minima correspond to the so-called
vacuum state of the field, making the problem well-defined but, surprisingly, exactly solvable in only a few
simple cases.

Relaxation dynamics between different vacua, commonly known as False Vacuum Decay (FVD), is a case
study that has significant impacts in broad and interdisciplinary research areas. Models have been proposed
to estimate the decay rate, entanglement generation at the onset of decay, the dynamics of decay products,
and the formation of topological defects at the end of the relaxation process. However, our current
knowledge is limited by a substantial lack of experimental observations.

This project aims to experimentally realize FVD and other challenging quantum field theories, both in the
perturbative and non-perturbative regimes, such as confinement physics, using ultracold atomic spin
mixtures through the proper mapping of the atomic wave function into a quantum field representation and
a unique setup that ensures extremely stable magnetic field conditions.