Non-Hermitian Efimov physics in dissipative three-body systems

Efimov effect is characterized by an infinite number of three-body bound states following a universal geometric scaling law at two-body resonances. In this paper, we investigate the influence of two-body losses which can be described by a complex scattering length ac on these states. Interestingly, the non-Hermiticity allows the system to have three-body bound states of energies with nonvanishing imaginary parts and real parts that may exceed the three-body or the atom-dimer scattering threshold. By taking the Cs133-Cs133-Li6 system as a concrete example, we calculate the trimer energies by solving the generalized Skorniakov-Ter-Martirosian equation and find such three-body bound states with energies that have positive real parts and obey a generalized geometric scaling law. Remarkably, we also find that in some regions these three-body bound states have longer lifetimes compared with the corresponding two-body bound states. In the absence of other loss mechanisms such as three-atom loss, the lifetimes for these trimer states can tend to infinity. Our work paves the way for the future exploration of few-body bound states in the complex plane.