Summary: Angular-momentum spatial distribution symmetry breaking in Rb by an external magnetic field
Janis Alnis and Marcis Auzinsh*
Department of Physics, University of Latvia, 19 Rainis blvd., Riga LV-1586, Latvia
Received 26 July 2000; published 16 January 2001
Excited-state angular-momentum alignment­orientation conversion for atoms with hyperfine structure in the
presence of an external magnetic field is investigated. Transversal orientation in these conditions is reported.
This phenomenon occurs under Paschen Back conditions at intermediate magnetic-field strength. Weak radia-
tion from a linearly polarized diode laser is used to excite Rb atoms in a cell. The laser beam is polarized at an
angle of /4 with respect to the external magnetic-field direction. Ground-state hyperfine levels of the 5S1/2
state are resolved using laser-induced fluorescence spectroscopy under conditions for which all excited 5P3/2
state hyperfine components are excited simultaneously. Circularly polarized fluorescence is observed to be
emitted in the direction perpendicular to both to the direction of the magnetic field B and direction of the light
polarization E. The obtained circularity is shown to be in quantitative agreement with theoretical predictions.
DOI: 10.1103/PhysRevA.63.023407 PACS number s : 32.80.Bx, 32.10.Fn
I. INTRODUCTION
In the absence of external forces an ensemble of unpolar-
ized atoms can only be aligned 1 by linearly polarized
light. The fact that the atoms are only aligned implies that,
although the magnetic sublevels of different mJ are popu-
lated unequally, magnetic sublevels of mJ and mJ are

Source: Auzinsh, Marcis - Department of Physics, University of Latvia

Collections: Physics