Cold Rydberg atoms in circular states

Circular-state Rydberg atoms are interesting in that they exhibit a unique combination of extraordinary properties; long lifetimes ($\sim$$n^{5}$), large magnetic moments ($l=|m|=n-1$) and no first order Stark shift. Circular states have found applications in cavity quantum electrodynamics and precision measurements [1,2], among other studies. In this work we present the production of circular states in an atom trapping apparatus using an adiabatic state-switching method (the crossed-field method [3]). To date, we have observed lifetimes of adiabatically prepared states of several milliseconds. Their relatively large ionization electric fields have been verified by time-of-flight signatures of ion trajectories. We intend to explore the magnetic trapping of circular state Rydberg atoms, as well as their production and interaction properties in ultra-cold and degenerate samples.\\[4pt] [1] P. Bertet et al., Phys. Rev. Lett., \textbf{88}, 14 (2002)\\[0pt] [2] M. Brune et al., Phys. Rev. Lett., \textbf{72}, 21 (1994)\\[0pt] [3] D. Delande and J.C. Gay, Europhys. Lett., \textbf{5}, 303-308 (1988).