The quantum-mechanical two-level system with dissipation and feedback: multimode applied electric-field case

1987 ◽  
Vol 65 (4) ◽  
pp. 417-420
Author(s):  
J. Grindlay
Keyword(s):  
Dipole Moment ◽  
Electric Field ◽  
Applied Electric Field ◽  
Quantum Mechanical ◽  
Third Order ◽  
First Order ◽  
Common Value ◽  
Induced Dipole ◽  
Upper Level

A two-level dissipative quantum-mechanical system subjected to a small applied multimode electric field plus a feedback term proportional to the induced dipole moment is discussed. The long-term behaviour of the induced dipole moment and of the upper level occupation probability is represented by a series expansion in terms of the applied electric-field amplitudes. First-order and third-order internal, external, and intrinsic polarizabilites are introduced and calculated for the model. Certain ratios of third-order to first-order polarizabilities are shown to have a common value for the internal, external, and intrinsic cases. Clausius–Mossotti relations for the linear and third-order susceptibilities are derived.

The quantum-mechanical two-level system with dissipation and feedback: application to nonlinear dielectric response

1986 ◽  
Vol 64 (6) ◽  
pp. 692-699 ◽  
Author(s):  
J. Grindlay
Keyword(s):  
Dipole Moment ◽  
Equations Of Motion ◽  
Power Series Expansion ◽  
Internal Field ◽  
Quantum Mechanical ◽  
Level System ◽  
Third Order ◽  
Long Time ◽  
Two Level Systems ◽  
Upper Level

A power-series expansion for long-time solutions is obtained for the density-matrix equations of motion describing a quantum-mechanical two-level system with dissipation and feedback. The resonances in the first- and third-order dipole contributions and the second-order upper level occupation probability are shown to be significantly affected by the feedback.The results are applied to the case of a uniformly polarized, finite, crystalline dielectric made up of two-level systems. Polarizabilities relating the dipole moment to each of the applied field, the internal field, and the macroscopic field are introduced and relations between them derived. The dipole-moment – macroscopic-field polarizabilities are shown in particular to be shape independent. Susceptibilities are defined and related to the single-system polarizabilities through generalized Clausius–Mossotti relations.

Two-level quantum mechanical system with decay: density matrix description and shifted frequency approximation

1985 ◽  
Vol 63 (12) ◽  
pp. 1525-1531
Author(s):  
D. C. Morgan ◽  
J. Grindlay
Keyword(s):  
Dipole Moment ◽  
Density Matrix ◽  
Equations Of Motion ◽  
Quantum Mechanical ◽  
Level System ◽  
Quantum Mechanical System ◽  
Third Order ◽  
Decay Times ◽  
Frequency Approximation

The shifted frequency approximation is used to solve the equations of motion for the density matrix describing a quantum mechanical two-level system, with decay, in an applied monochromatic electric field. Expressions are obtained for the transient and the long-term linear electric dipole moment and occupation probability, and the long-term third-order dipole moment. The results are valid across the frequency spectrum, including resonance, provided the phenomenological decay times for the system are not too large or too close in value.

Solvatochromism and Electroabsorption Studies of Drug Carriers

2014 ◽  
Vol 807 ◽  
pp. 169-176
Author(s):  
R. Jothilakshmi ◽  
R. Rajeswari ◽  
E. Thanikaivelan
Keyword(s):  
Drug Delivery ◽  
Dipole Moment ◽  
Electric Field ◽  
Applied Electric Field ◽  
Spectral Properties ◽  
Dipole Moments ◽  
Drug Carriers ◽  
Higher Order ◽  
Third Order ◽  
The Third

2, 6-Diaminoanthraquinone is used in drug delivery. The absorption and fluorescence spectral properties of 2,6-Diaminoanthraquinone (DAAQ) have been investigated in a series of organic solvents with different polarity functions ranging from 0.207 to 0.762.The different solvents used are Tetrahydrofuran (THF) (0.207), Dimethylformamide (DMF) (0.404), ethanol (0.654) and Methonal (0.762).The fluorescence shifts are more pronounced than the absorption shifts indicating that the change in dipole moment is positive. The change in dipole moment and the ratio of the dipole moments are determined and discussed by Solvatochromism method. The third order nonlinearity of 2,6-DAAQ in PVA dissolved in DMF solution is determined using Electroabsorption. Higher order nonlinearities can be deduced on successful recording of the stark spectrum at the higher order of the applied electric field.

DIRECTIONAL DIFFUSION OF K ATOMS ON A GaAs(110) SURFACE

2006 ◽  
Vol 05 (06) ◽  
pp. 895-900 ◽  
Author(s):  
NOBUYUKI ISHIDA ◽  
AGUS SUBAGYO ◽  
KAZUHISA SUEOKA
Keyword(s):  
Dipole Moment ◽  
Electric Field ◽  
Radial Direction ◽  
Negative Sample ◽  
Directional Diffusion ◽  
Sample Bias ◽  
Induced Dipole ◽  
High K ◽  
Scanning Area ◽  
The Relationship

We performed STM measurements on the K/GaAs (110) surface with high K coverage. The K atoms gradually disappeared while scanning the tip over the surface at negative sample bias voltage. The phenomenon strongly occurred over the scanning area and can be explained by the field-induced surface diffusion from the scanning area to radial direction. Considering the interaction between the dipole moment of the adsorbed K atoms and the electric field, we discuss the relationship between the static and induced dipole moment of K atoms on a GaAs (110) surface.

scholarly journals MODIFIED WAVE EQUATION FOR SPINLESS PARTICLES AND ITS SOLUTIONS IN AN EXTERNAL MAGNETIC FIELD

2013 ◽  
Vol 28 (06) ◽  
pp. 1350014 ◽  
Author(s):  
S. I. KRUGLOV
Keyword(s):  
Magnetic Field ◽  
Wave Equation ◽  
External Magnetic Field ◽  
Quantum Mechanical ◽  
Third Order ◽  
Modified Dispersion Relation ◽  
First Order ◽  
The Third ◽  
Uniform External Magnetic Field ◽  
Schrödinger Form

The wave equation for spinless particles with the Lorentz violating term is considered. We formulate the third-order in derivatives wave equation leading to the modified dispersion relation. The first-order formalism is considered and the density matrix is obtained. The Schrödinger form of equations is presented and the quantum-mechanical Hamiltonian is found. Exact solutions of the wave equation are obtained for particles in the constant and uniform external magnetic field. The change of the synchrotron radiation radius due to quantum gravity corrections is calculated.

The driven quantum-mechanical two-level system: small fields and long relaxation times

1987 ◽  
Vol 65 (1) ◽  
pp. 82-87
Author(s):  
J. Grindlay
Keyword(s):  
Relaxation Times ◽  
Formal Theory ◽  
Quantum Mechanical ◽  
Third Harmonic ◽  
Resonance Frequencies ◽  
Small Fields ◽  
Rotating Wave ◽  
Upper Level ◽  
Term Response

A formal theory of the long-term response of a dissipative two-level quantum-mechanical system to a monochromatic applied electric field is used to describe the fundamental and third-harmonic resonances in the small-field and long relaxation-times regime. Resonance frequencies, including Bloch–Siegert shifts, and resonance amplitudes for the dipole-moment components and the upper level probability function are obtained. A comparison with the rotating-wave approximation is made.

A Fourier transform treatment of the quantum mechanical two-level system in an applied electric field. I. Single field case

1984 ◽  
Vol 62 (8) ◽  
pp. 741-750 ◽  
Author(s):  
J. Grindlay ◽  
J. Mizia
Keyword(s):  
Fourier Transform ◽  
Differential Equations ◽  
Electric Field ◽  
Numerical Integration ◽  
Applied Electric Field ◽  
Approximate Expression ◽  
Quantum Mechanical ◽  
Level System ◽  
Single Field ◽  
Applied Fields

Fourier transform techniques are used to obtain an approximate expression for the response of a quantum mechanical two-level system to a small monochromatic applied electric field. A comparison with the results of a numerical integration of the differential equations shows that the approximation is equally satisfactory close to and far from resonance. The method is easily extended to two or more applied fields.

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