Species-selective lattice launch for precision atom interferometry

Abstract

Long-baseline precision tests based on atom interferometry require drastic control over the initial external degrees of freedom of atomic ensembles to reduce systematic effects. The use of optical lattices (OLs) is a highly accurate method to manipulate atomic states in position and momentum allowing excellent control of the launch in atomic fountains. The simultaneous lattice launch of two atomic species, as required in a quantum test of the equivalence principle, is however problematic due to crosstalk effects. In this article, we propose to selectively address two species of alkalines by applying two OLs at or close to magic-zero wavelengths of the atoms. The proposed scheme applies in general for a pair of species with a vastly different ac Stark shift to a laser wavelength. We illustrate the principle by studying a fountain launch of condensed ensembles of 87 Rb and 41 K initially co-located. Numerical simulations confirm the fidelity of our scheme up to few nm and nm s −1 in inter-species differential position and velocity, respectively. This result is a pre-requisite for the next performance level in precision tests.

Comment on ‘Species-selective lattice launch for precision atom interferometry’

“…Our new and more precise measurement, ( ) l = 768.9701 5 nm zero [3] deviates from Chamakhi's value by more than 20σ. State of the art calculations [4,5] are also consistent with our measurements [2,3] but inconsistent with the l zero value tabulated in [1]. In this Comment we explain this discrepancy.…”

“…Using inverse lifetimes from [6,7] in Chamakhi's equation (7) produces a calculated tune-out wavelength of l zero = 768.9691(20) nm. This l zero is 9.4 pm higher than Chamakhi's value in [1]. It also demonstrates an uncertainty of 2.0 pm due to (assumed uncorrelated) uncertainties in decay rates.…”

Decoherence Spectroscopy for Atom Interferometry

“…These λ zero measurements test theoretical polarizability spectra α(ω) described in references [22][23][24][25][26][27][28][29][30][31][32][33]. To measure λ zero , we apply an irradiance gradient on the paths of a Mach-Zehnder atom beam interferometer [37][38][39].…”

“…Tune-out wavelengths occur at roots in the dynamic polarizability spectrum of an atom, and λ zero measurements can serve as benchmark tests of atomic structure calculations [22][23][24][25][26][27][28][29][30][31][32][33]. Here we use decoherence to calibrate the frequency-axis for light-induced phase shift spectra, as we discuss in more detail in Sections 2-4.…”

Potassium tune-out-wavelength measurement using atom interferometry and a multipass optical cavity

“…Precise λ zero measurements [1][2][3][4][5] serve as a means to study several atomic properties including lifetimes; oscillator strengths; oscillator strength ratios; atomic scalar, vector, and tensor polarizabilities and hyperpolarizabilities; the polarization of atomic core electrons; core-valence electron correlations; and relativistic and QED effects on atomic transition amplitudes [6][7][8][9][10][11][12][13][14][15]. Improved knowledge of λ zero values can also be important for several experiments that use species-specific and state-specific optical dipole potentials created with light near a tune-out wavelength [16][17][18][19][20][21][22][23]. Tune-out wavelengths, also known as magic-zero wavelengths, were mentioned in 2004 by Safronova et al [6].…”