Time-dependent molecular fields created by the interaction of an external electromagnetic field with a molecular system

2014 ◽  
Vol 114 (24) ◽  
pp. 1645-1659 ◽  
Author(s):  
Michael Baer
Keyword(s):  
Electromagnetic Field ◽  
Molecular System ◽  
External Electromagnetic Field ◽  
Time Dependent ◽  
Molecular Fields

A CAUSAL, LORENTZ COVARIANT AND GAUGE-INVARIANT VACUUM FOR A DIRAC FIELD IN THE PRESENCE OF AN EXTERNAL ELECTROMAGNETIC FIELD

1992 ◽  
Vol 07 (09) ◽  
pp. 793-800
Author(s):  
A.Z. CAPRI ◽  
S.M. ROY
Keyword(s):  
Electromagnetic Field ◽  
External Electromagnetic Field ◽  
Time Dependent ◽  
Dirac Field ◽  
Gauge Invariant ◽  
Bogoliubov Transformations

We show how to construct, for a Dirac field coupled to time-dependent external electromagnetic field, an instantaneous causal vacuum that depends only on the (planar) hypersurface of instantaneity and is independent of coordinates and gauges. The instantaneous particle states are then defined covariantly and connected to states defined with respect to other hypersurfaces of instantaneity by Bogoliubov transformations.

LORENTZ-COVARIANT AND GAUGE-INVARIANT INSTANTANEOUS VACUUM FOR EXTERNAL FIELD PROBLEMS

1994 ◽  
Vol 09 (07) ◽  
pp. 1025-1041
Author(s):  
A. Z. CAPRI ◽  
S. M. ROY
Keyword(s):  
Electromagnetic Field ◽  
External Field ◽  
Gauge Invariance ◽  
External Electromagnetic Field ◽  
Time Dependent ◽  
Dirac Field ◽  
Spacelike Surface ◽  
Bogoliubov Transformation ◽  
Gauge Invariant ◽  
Lorentz Covariance

For a Dirac field coupled to time-dependent external electromagnetic field we define an instantaneous (on a fixed spacelike surface) causal vacuum respecting Lorentz covariance and gauge invariance. The instantaneous particle states on this surface are then defined covariantly and connected to states at another time by a Bogoliubov transformation.

scholarly journals PSEUDOCLASSICAL MODEL OF SPINNING PARTICLE WITH ANOMALOUS MAGNETIC MOMENTUM

1993 ◽  
Vol 08 (05) ◽  
pp. 463-468 ◽  
Author(s):  
D.M. GITMAN ◽  
A.V. SAA
Keyword(s):  
Electromagnetic Field ◽  
External Electromagnetic Field ◽  
Invariant Form ◽  
Pauli Equation ◽  
Spinning Particle ◽  
Dirac Quantization

A generalization of the pseudoclassical action of a spinning particle in the presence of an anomalous magnetic momentum is given. The action is written in reparametrization and supergauge invariant form. The Dirac quantization, based on the Hamiltonian analyzes of the model, leads to the Dirac-Pauli equation for a particle with an anomalous magnetic momentum in an external electromagnetic field. Due to the structure of first class constraints in that case, the Dirac quantization demands for consistency to take into account an operator’s ordering problem.

SYMMETRY PROPERTIES IN THE STUDY OF THE RAYLEIGH-TYPE OPTICAL MIXING SIGNAL IN PRESENCE OF A THERMAL BATH

2013 ◽  
Vol 22 (01) ◽  
pp. 1350007
Author(s):  
J. L. PAZ ◽  
A. MASTRODOMENICO ◽  
M. A. IZQUIERDO
Keyword(s):  
Electromagnetic Field ◽  
Molecular System ◽  
Thermal Bath ◽  
Bloch Equations ◽  
System A ◽  
Symmetry Properties ◽  
Intensity Response ◽  
Optical Mixing ◽  
Cumulant Expansions

In this work are studied the symmetry properties of the Rayleigh-type optical mixing signal of a two-level molecular system immersed in a thermal bath and irradiated by a classical electromagnetic field. The solvent induces a random shift of the Bohr frequency in the molecular system. A methodology based in cumulant expansions is employed to obtain the average of the coherences, populations, and susceptibilities of Fourier components associated, calculated by the optical stochastic Bloch equations. These symmetry properties show the dependence of the measured spectra with the variations in the frequencies of the incident fields. Our results show that the inclusion of the thermal bath diminishes the intensity response as well it promotes the loss of the symmetry properties, compared with the same results in the absence of the bath.

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