Dynamically probing three-body systems in cold gases

Knowing the intrinsic aspects of few-body systems, such as binding energies, and lifetimes, is highly desirable since they affect the macroscopic properties of a gas. On a two-body level there are well-established dynamical protocols addressing their attributes, however, this is not the case for three-body systems. Our study focuses on the dynamics of three bosons triggered by a double sequence of magnetic field pulses. This Ramsey-like protocol permits the creation of trimers and by varying the dark time between the two pulses an oscillatory pattern emerges in the fraction of formed trimers. The spectra of these interference fringes provide simultaneously the binding energy of trimers as well as their lifetimes, and they are robust against thermal effects. This means that the proposed dynamical protocol can be potentially used to determine the intrinsic characteristics of exotic few-body states, e.g. Efimov states, regardless the sign or the magnitude of the scattering length.