Prog. Theor. Phys. Vol. 80 No. 3 (1988) pp. 433-448

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Stochastic Liouville Equation for Weakly Driven System. II

— Application to a Quantal Spin —

Mizuhiko Saeki

Department of Physics, Ochanomizu University, Tokyo 112

(Received March 7, 1988)

Abstract:

The time-convolutionless stochastic equation derived in a previous paper is applied to a quantal spin interacting weakly with its surroundings under decoupled initial condition, up to second order in powers of random perturbations. The transverse and longitudinal susceptibilities are derived from the stationary solutions. The transverse and longitudinal spectra are displayed and are compared with the ones derived from the time-convolution equation in the conventional Markoffian approximation, and with the ones by the method of second-order spin relaxation theory and Kubo's theory. It is shown that the line shape of transverse spectrum is enhanced over the Lorentzian at the resonance region, due to the effects of interference of the external driving field and the random interaction.

URL : http://ptp.ipap.jp/link?PTP/80/433/
DOI : 10.1143/PTP.80.433

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Citing Article(s) :

Progress of Theoretical Physics Vol. 89 No. 3 (1993) pp. 607-622 :
Relation between Method of TCL Equation with External Terms and Relaxation Method

Mizuhiko Saeki
Progress of Theoretical Physics Vol. 98 No. 5 (1997) pp. 1025-1043 :
Transverse Susceptibilities of a Quantal Spin (S=1/2)

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Progress of Theoretical Physics Vol. 114 No. 5 (2005) pp. 907-927 :
A Quantum Field Theoretical Approach to the TCLE Method

Mizuhiko Saeki
Progress of Theoretical Physics Vol. 115 No. 1 (2006) pp. 1-22 :
Linear Response in an Interacting Boson System

Mizuhiko Saeki