Precise determination of h/mRb using Bloch oscillations and atomic interferometry: A mean to deduce the fine structure constant

Abstract

Abstract. We use Bloch oscillations to transfer coherently many photon momenta to atoms. Then we can measure accurately the ratio h/m Rb and deduce the fine structure constant α. The velocity variation due to the Bloch oscillations is measured thanks to Raman transitions. In a first experiment, two Raman π pulses are used to select and measure a very narrow velocity class. This method yields to a value of the fine structure constant α −1 = 137.035 998 84 (91) with a relative uncertainty of about 6.6 ppb. More recently we use an atomic interferometer consisting in two pairs of π/2 pulses. We present here the first results obtained with this method.

CODATA Recommended Values of the Fundamental Physical Constants: 2010

“…A value of h/m( 87 Rb) with a relative uncertainty of 9.2 × 10 −9 and in agreement with the earlier result, obtained from a new LKB experiment using combined Bloch oscillations and atom interferometry, was subsequently reported by Cadoret et al (2008). In this approach Bloch oscillations are employed to transfer a large number of photon momenta to rubidium atoms and an atom interferometer is used to accurately determine the resulting variation in the velocity of the atoms.…”

“…The experiment of the LKB group from which the result given in Eq. ( 236) was obtained is described in the paper by Bouchendira et al (2011), the references cited therein; see also Cadoret et al (2009Cadoret et al ( , 2011Cadoret et al ( , 2008; Cladé et al (2010). It is worth noting, however, that the reduction in uncertainty of the 2008 result by over a factor of 7 was achieved by reducing the uncertainties of a number of individual components, especially those due to the alignment of beams, wave front curvature and Gouy phase, and the second order Zeeman effect.…”

Astrophysics, atomic clocks and fundamental constants

“…3. Determination of the fine structure constant α. References: measurements of the electron anomalous magnetic moment: UWash87 [31] and HarvU06 [32], HarvU08 [33]; theory: th98 [34], th02 [35], th06 [36], th07 [37]; atomic recoil data from h/m in Cs [38] and Rb [39,40].…”

“…The measurements of recoil frequencies in atomic interferometry now provide us with such accurate values of the fine structure constant [38][39][40], which make the α value more reliable.…”

Absorción de radiación en átomos y su aplicación en la experimentación

“…l presente trabajo esta basado en estudios previos de interferometría atómica como los realizados por M. Cadoret, E De Mirades, P Cladé y colaboradores en el laboratorio Laboratoire Kastler Brossel [9]; D.S. Weiss, B.C.…”