Nonexponential tunneling decay of a single ultracold atom

Abstract

By using an exact analytical approach to the time evolution of decay we investigate the tunneling decay of ultracold single atoms, to discuss the conditions for deviations of the exponential decay law. We find that $R$, given by the ratio of the energy of the decaying fragment ${\mathcal{E}}_r$ to its corresponding width ${\Gamma }_r$, is the relevant quantity in this study. When $R$ is less than $0.3$ the decay of the atom goes to a good approximation for the first few lifetimes as $\exp (-{\Gamma }_{r}t/2\hslash )t^{-3/2}$. We also find that for values of $R\sim 1$, the nonexponential behavior occurs in a post-exponential regime that goes as $t^{-3}$ after around a dozen of lifetimes. The above conditions depend on suitable designed potential parameters and suggest that for values $R\lesssim 1$, the experimental verification of nonexponential decay might be possible.

9 pages, 7 figures

References in corpus (6)

• Many-Body Physics with Ultracold Gases
• How does an interacting many-body system tunnel through a potential barrier to open space?
• Decay by tunneling of Bosonic and Fermionic Tonks-Girardeau Gases
• Tunneling Theory for Tunable Open Quantum Systems of Ultracold Atoms in One-Dimensional Traps
• Hermitian and non-Hermitian formulations of the time evolution of quantum decay
• Analytical study of quadratic and non-quadratic short-time behavior of quantum decay

Cited by in corpus (3)

• Formal Aspects of Quantum Decay
• Underlying non-Hermitian character of the Born rule in open quantum systems
• Effect of the resonance spectra in the propagation of two decaying entangled particles