Jeudi 3 juin 2004
Liquid, solid and cold gaseous helium provide environments to neutral impurity atoms suitable for testing fundamental atomic and molecular physics.
Here, I discuss mainly alkali-metal atoms in cold helium gas, after showing briefly some unique properties of such atoms in superfluid helium. I first present a method to gently produce gaseous alkali atoms in a glass cell cooled to a low temperature. Since the produced atoms have a lifetime and a spin (electron spin) relaxation time as long as 100 s, they allow the precise measurement of the atomic permanent electric dipole moment (EDM).
This measurement offers a direct test of time-reversal symmetry. Then, I turn to alkali-helium molecules (MHen ; n=1,2,...), which are formed only at a low temperature of about 10 K.
I discuss the structure and growth of these molecules, on the basis of their observed spectra in the visible and near infrared.
RECRUTEMENT ACCES DIRECT
Le département de physique
Fête de la Science 2018 