On the role of period-amplitude dependence in the study of inertial effects and dipole-dipole coupling

• Published in: Chemical physics letters Vol. 123; no. 5; pp. 416 - 422
• Main Author: Coffey, William
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 24.01.1986; Elsevier Science
• Subjects: Atomic and molecular physics; Effects of atomic and molecular interactions on electronic structure; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Physics; Time-dependent phenomena: excitation and relaxation processes, and reaction rates; Fluid state; Dipolar interaction; Temperature; Molecular dynamics; Theoretical study; Non linear effect; Velocity correlation function; Polar molecule; Dielectric relaxation; Far infrared spectrum
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/0009-2614(86)80034-3

An exact analytical formula for the complex polarizability of two dipoles constrained to rotate in two dimensions under the influence of their mutual dipole-dipole coupling is derived subject to the condition that the motion is lightly damped and that non-linear effects are weak. The inclusion of non-linear effects due to the cosine potential of dipole-dipole interaction even in first approximation indicates that the natural frequency of oscillation of the angular velocity correlation functions depends on their amplitude and thus on the temperature. The frequency of maximum far-infrared power absorption is found to depend on temperature in accordance with an earlier finding of Marchesoni. The Q factor of the system appears to decrease with temperature in the same way as the natural frequency, but the bandwidth is relatively unaffected.