Shift of holes in spectral lines due to time dependent perturbation

1976 ◽  
Vol 54 (24) ◽  
pp. 2422-2428 ◽  
Author(s):  
R. P. Srivastava
Keyword(s):  
Excited States ◽  
Radiative Decay ◽  
Practical Importance ◽  
Perturbation Expansion ◽  
Spectral Lines ◽  
The Other ◽  
Time Dependent ◽  
Strongly Coupled ◽  
Expansion Yield ◽  
Rotating Wave

The radiative decay of an atom with two excited states, one decaying and the other non-decaying, coupled by a time dependent perturbation, is investigated. The hole in the emission line is found to be shifted by an amount equal to the frequency of the time dependent perturbation. The practical importance of this effect is discussed. It is also noticed that the two methods of solution, one by making the rotating-wave approximation and the other by a perturbation expansion, yield different results, especially in the case when the two excited states are strongly coupled.

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Restriction of Access to Dark State: A New Mechanistic Model for Heteroatom-Containing AIE Systems

2019 ◽  
Author(s):  
Yujie Tu ◽  
Junkai Liu ◽  
Haoke Zhang ◽  
Qian Peng ◽  
Jacky W. Y. Lam ◽  
...  
Keyword(s):  
Excited States ◽  
Radiative Decay ◽  
Molecular Design ◽  
Mechanistic Model ◽  
Zinc Ion ◽  
Easy Access ◽  
Triplet States ◽  
Dark State ◽  
Ion Probe ◽  
Π State

Aggregation-induced emission (AIE) is an unusual photophysical phenomenon and provides an effective and advantageous strategy for the design of highly emissive materials in versatile applications such as sensing, imaging, and theragnosis. "Restriction of intramolecular motion" is the well-recognized working mechanism of AIE and have guided the molecular design of most AIE materials. However, it sometimes fails to be workable to some heteroatom-containing systems. Herein, in this work, we take more than one excited state into account and specify a mechanism –"restriction of access to dark state (RADS)" – to explain the AIE effect of heteroatom-containing molecules. An anthracene-based zinc ion probe named APA is chosen as the model compound, whose weak fluorescence in solution is ascribed to the easy access from the bright (π,π*) state to the closelying dark (n,π*) state caused by the strong vibronic coupling of the two excited states. By either metal complexation or aggregation, the dark state is less accessible due to the restriction of the molecular motion leading to the dark state and elevation of the dark state energy, thus the emission of the bright state is restored. RADS is found to be powerful in elucidating the photophysics of AIE materials with excited states which favor non-radiative decay, including overlap-forbidden states such as (n,π*) and CT states, spin-forbidden triplet states, which commonly exist in heteroatom-containing molecules.

Time-dependent behavior of nitric oxide excited states under the effect of electron impact

2021 ◽  
Vol 28 (2) ◽  
pp. 024503
Author(s):  
Mohammed amin Ferdi ◽  
Abdelaaziz Bouziane ◽  
Mourad Djebli
Keyword(s):  
Nitric Oxide ◽  
Electron Impact ◽  
Excited States ◽  
Time Dependent ◽  
Dependent Behavior

scholarly journals Ground- and excited-state characteristics in photovoltaic polymer N2200

RSC Advances ◽  
2021 ◽  
Author(s):  
Guanzhao Wen ◽  
Xianshao Zou ◽  
Rong Hu ◽  
Jun Peng ◽  
Zhifeng Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Steady State ◽  
Excited States ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Time Dependent ◽  
Functional Theory ◽  
Time Resolved ◽  
Dependent Density

Ground- and excited-states properties of N2200 have been studied by steady-state and time-resolved spectroscopies as well as time-dependent density functional theory calculations.

scholarly journals Spread of Entanglement in Non-Relativistic Theories

2018 ◽  
Vol 2018 ◽  
pp. 1-27
Author(s):  
Sagar F. Lokhande
Keyword(s):  
Broad Class ◽  
Entanglement Entropy ◽  
Time Dependent ◽  
Quantum Field Theories ◽  
Strongly Coupled ◽  
Conformal Field ◽  
Instantaneous Power ◽  
Holographic Entanglement Entropy ◽  
Quantum Quenches ◽  
Good Order

We use a simple holographic toy model to study global quantum quenches in strongly coupled, hyperscaling-violating-Lifshitz quantum field theories using entanglement entropy as a probe. Generalizing our conformal field theory results, we show that the holographic entanglement entropy of small subsystems can be written as a simple linear response relation. We use this relation to derive a time-dependent first law of entanglement entropy. In general, this law has a time-dependent term resembling relative entropy which we propose as a good order parameter to characterize out-of-equilibrium states in the post-quench evolution. We use these tools to study a broad class of quantum quenches in detail: instantaneous, power law, and periodic.

Excited states of analogue models of M-bacteriochlorophylls (M = Mg, Zn) in the photosynthetic reaction center: a time-dependent density functional theory study

2002 ◽  
Vol 06 (10) ◽  
pp. 617-625 ◽  
Author(s):  
Yoichi Yamaguchi
Keyword(s):  
Electron Transfer ◽  
Excited States ◽  
Density Functional ◽  
Photosynthetic Reaction Center ◽  
Excited Electron ◽  
Time Dependent ◽  
Analogue Model ◽  
Functional Theory ◽  
Special Pair ◽  
Dependent Density

Using time-dependent density functional theory (TDDFT), the excited states of the analogue model Mg -bacteriochlorophyll b - imidazole ( BChl -Im) dimer (P) for a special pair in the photosynthetic reaction center (RC) of Rhodopseudomonas (Rps.) viridis were examined. The calculated low-lying excited states and optimal geometries are in good agreement with experimental data. The order of the lowest unoccupied molecular orbital (LUMO) energies of P, the monomeric "accessory" BChl -Im (B), and bacteriopheophytin b ( H ) indicates the possibility of the light-induced electron transfer from P to H via B. The Im ligand of B destabilizes Goutermann's four-orbitals of BChl by 0.3-0.4 eV. With no energetic difference in the LUMOs between H and BChl , the Im ligands of P and B play an important role in providing a greater energetic gradient to the LUMOs along with the pathway for the excited-electron transfer in RC, resulting in the reduced reverse electron transfer from H to P (via B). Thus it is expected that the asymmetric Mg -Im interactions will directly affect the pathway of the excited-electron transfer. Using the deformed heterodimer (P') formed by the BChl halves with and without Im as the primary donor model, its cation radical P'+ was calculated as to whether the experimental asymmetric spin-density distribution can reproduce. The excited states of the analogue model Zn - BChl -Im dimer for a special pair in RC of the recently discovered Acidiphilium rubrum were also examined for a comparison with P.

OPTICAL PHONON EFFECT IN AN ASYMMETRIC QUANTUM DOT QUBIT

2012 ◽  
Vol 10 (07) ◽  
pp. 1250077 ◽  
Author(s):  
ZHAO-HUA DING ◽  
YONG SUN ◽  
JING-LIN XIAO
Keyword(s):  
Quantum Dot ◽  
Excited States ◽  
Oscillation Period ◽  
Present System ◽  
Superposition State ◽  
Strongly Coupled ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum ◽  
Electron Phonon Coupling ◽  
Increasing Function

We investigate the eigenenergies and the eigenfunctions of the ground and the first excited states of an electron, which is strongly coupled to LO-phonon in an asymmetric quantum dot (QD) by using variational method of Pekar type. The present system may be used as a two-level qubit. When the electron is in the superposition state of the ground and the first excited states, the probability density of the electron oscillates in the QD with a certain period. It is found that the oscillation period is an increasing function of the transverse and the longitudinal effective confinement lengths of the QD, whereas it is a decreasing one of the electron–phonon coupling strength.

FRW viscous fluid cosmological model with time-dependent inhomogeneous equation of state

2017 ◽  
Vol 15 (01) ◽  
pp. 1830001 ◽  
Author(s):  
G. S. Khadekar ◽  
Deepti Raut
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Quadratic Form ◽  
State Parameter ◽  
The Other ◽  
Time Dependent ◽  
Inhomogeneous Equation ◽  
Field Equations ◽  
Equation Of State Parameter ◽  
Viscous Models

In this paper, we present two viscous models of non-perfect fluid by avoiding the introduction of exotic dark energy. We consider the first model in terms of deceleration parameter [Formula: see text] has a viscosity of the form [Formula: see text] and the other model in quadratic form of [Formula: see text] of the type [Formula: see text]. In this framework we find the solutions of field equations by using inhomogeneous equation of state of form [Formula: see text] with equation of state parameter [Formula: see text] is constant and [Formula: see text].

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