Observation of a narrow inner-shell orbital transition in atomic erbium at 1299 nm

Abstract

We report on the observation and coherent excitation of atoms on the narrow inner-shell orbital transition, connecting the erbium ground state [Xe]4f 12 ( 3 H6)6s 2 to the excited state [Xe]4f 11 ( 4 I15 /2 ) 0 5d( 5 D3 /2 )6s 2 ( 15 /2, 3 /2) 0 7 . This transition corresponds to a wavelength of 1299 nm and is optically closed. We perform high-resolution spectroscopy to extract the gJ -factor of the 1299-nm state and to determine the frequency shift for four bosonic isotopes. We further demonstrate coherent control of the atomic state and extract a lifetime of 178( 19) ms which corresponds to a linewidth of 0.9(1) Hz. The experimental findings are in good agreement with our semi-empirical model. In addition, we present theoretical calculations of the atomic polarizability, revealing several different magic-wavelength conditions. Finally, we make use of the vectorial polarizability and confirm a possible magic wavelength at 532 nm.

New opportunites for interactions and control with ultracold lanthanides

“…Such transitions have Hz-range linewidth and, importantly, a wavelength in the technologically useful near-infrared range. Such transitions have recently been observed in dysprosium (λ = 1001nm) [12] and erbium (λ = 1299nm) [13]. For erbium, a near-magic-wavelength condition and quantum coherent manipulation has been also demonstrated.…”

“…In experiments, the scalar, vectorial, and tensorial dynamical polarizability at specific wavelengths have been measured for erbium [80], dysprosium [81][82][83][84], and thulium [79,85]. The anisotropic polarizability and spindependent atom-light interaction have been then used to realize "tune-out" [81] and "magic [13,83] wavelength conditions between ground and excited states, as well as techniques for control of spin and motional dynamics, discussed in the following section.…”