https://doi.org/10.1140/epjd/e2002-00227-7
Laser cooling of molecules via single spontaneous emission
Fachbereich Physik der Universität Konstanz, Fach M674, 78457 Konstanz,
Germany
Corresponding authors: a ooi@spock.physik.uni-konstanz.de - b Peter.Marzlin@uni-konstanz.de - c Juergen.Audretsch@uni-konstanz.de
Received:
25
June
2002
Revised:
28
September
2002
Published online:
12
November
2002
A general scheme for reducing the center-of-mass entropy is proposed. It is
based on the repetition of a cycle, composed of three concepts: velocity
selection, deceleration and irreversible accumulation. Well-known laser
techniques are used to represent these concepts: Raman 
-pulse for
velocity selection, STIRAP for deceleration, and a single spontaneous
emission for irreversible accumulation. No closed pumping cycle nor repeated
spontaneous emissions are required, so the scheme is applicable to cool a
molecular gas. The quantum dynamics are analytically modelled using the
density matrix. It is shown that during the coherent processes the gas is
translationally cooled. The internal states serve as an entropy sink, in
addition to spontaneous emission. This scheme provides new possibilities to
translationally laser-cool molecules for high precision molecular
spectroscopy and interferometry.
PACS: 32.80.Pj – Optical cooling of atoms; trapping / 33.80.Ps – Optical cooling of molecules; trapping / 42.50.Vk – Mechanical effects of light on atoms, molecules, electrons, and ions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003
