Adiabatic orientation of rotating dipole molecules in an external field

Abstract

The induced polarization of a beam of polar clusters or molecules passing through an electric or magnetic field region differs from the textbook Langevin-Debye susceptibility. This distinction, which is important for the interpretation of deflection and focusing experiments, arises because instead of acquiring thermal equilibrium in the field region, the beam ensemble typically enters the field adiabatically, i.e., with a previously fixed distribution of rotational states. We discuss the orientation of rigid symmetric-top systems with a body-fixed electric or magnetic dipole moment. The analytical expression for their "adiabatic-entry" orientation is elucidated and compared with exact numerical results for a range of parameters. The differences between the polarization of thermodynamic and "adiabatic-entry" ensembles, of prolate and oblate tops, and of symmetric-top and linear rotators are illustrated and identified.

arXiv comment18 pages, 4 figures

References in corpus (3)

• Magnetic structure of free cobalt clusters studied with Stern-Gerlach deflection experiments
• Water vapor at a translational temperature of one kelvin
• Electrostatic deflection of the water molecule, a fundamental asymmetric rotor

Cited by in corpus (5)

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• Electrostatic deflection of a molecular beam of massive neutral particles: Fully field-oriented polar molecules within superfluid nanodroplets
• Direct detection of polar structure formation in helium nanodroplets by beam deflection measurements
• Beam broadening of polar molecules and clusters in deflection experiments
• Probing the presence and absence of metal-fullerene electron transfer reactions in helium nanodroplets by deflection measurements