scholarly journals Monitoring of Nonadiabatic Effects in Individual Chromophores by Femtosecond Double-Pump Single-Molecule Spectroscopy: A Model Study

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 231
Author(s):  
Maxim Gelin ◽  
Elisa Palacino-González ◽  
Lipeng Chen ◽  
Wolfgang Domcke
Keyword(s):  
Population Dynamics ◽  
Density Matrix ◽  
Strong Coupling ◽  
Single Molecule ◽  
Weak Coupling ◽  
Electronic States ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Electronic Density ◽  
Optical Gap

We explore, by theoretical modeling and computer simulations, how nonadiabatic couplings of excited electronic states of a polyatomic chromophore manifest themselves in single-molecule signals on femtosecond timescales. The chromophore is modeled as a system with three electronic states (the ground state and two non-adiabatically coupled excited states) and a Condon-active vibrational mode which, in turn, is coupled to a harmonic oscillator heat bath. For this system, we simulate double-pump single-molecule signals with fluorescence detection for different system-field interaction strengths, from the weak-coupling regime to the strong-coupling regime. While the signals are determined by the coherence of the electronic density matrix in the weak-coupling regime, they are determined by the populations of the electronic density matrix in the strong-coupling regime. As a consequence, the signals in the strong coupling regime allow the monitoring of nonadiabatic electronic population dynamics and are robust with respect to temporal inhomogeneity of the optical gap, while signals in the weak-coupling regime are sensitive to fluctuations of the optical gap and do not contain information on the electronic population dynamics.

THE DYNAMICS OF GEOMETRIC DISCORD AND ITS TRANSFER IN ATOM-CAVITY-RESERVOIR SYSTEM

2013 ◽  
Vol 27 (24) ◽  
pp. 1350136 ◽  
Author(s):  
TAO WU ◽  
XUE-KE SONG ◽  
LIU YE
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Quantum Discord ◽  
Dissipative System ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Geometric Quantum Discord ◽  
Reservoir System

The dynamics of geometric discord (GD) and its transfer in a dissipative system consisting of two independent atom-cavity-reservoir subsystems under the strong coupling and the weak coupling regimes is studied. It is shown that the GD of the atoms and the cavities oscillatorily decays to zero while the reservoirs begin to present nonzero geometric quantum discord already immediately after t = 0 in the strong coupling regime. However, in the weak coupling regime, the GD between the atoms progressively decays becoming zero and the discord between the reservoirs arises from zero to a steady value, while the cavities remain almost uncorrelated during the evolution. We also show that the amount of GD contained in atoms and reservoirs depends on the purity p and it is proportional to p, the smaller the value of p the smaller the amount of GD. It is worth noting that, in both strong coupling and the weak coupling regimes, the results show that GD initially stored in the atoms will eventually be completely transferred to the reservoirs, independent of the parameters, but the transfer is mediated via the cavities in the strong coupling regime, while it is almost directly in the weak coupling regime.

Anomalies in Strongly Coupled Harmonic Quantum Brownian Motion

2013 ◽  
Vol 20 (01) ◽  
pp. 1350002 ◽  
Author(s):  
F. Giraldi ◽  
F. Petruccione
Keyword(s):  
Time Evolution ◽  
Power Law ◽  
Weak Coupling ◽  
Inverse Power ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Spectral Densities ◽  
Inverse Power Law ◽  
Critical Configurations ◽  
Long Time

The exact dynamics of a quantum damped harmonic oscillator coupled to a reservoir of boson modes has been formally described in terms of the coupling function, both in weak and strong coupling regime. In this scenario, we provide a further description of the exact dynamics through integral transforms. We focus on a special class of spectral densities, sub-ohmic at low frequencies, and including integrable divergencies referred to as photonic band gaps. The Drude form of the spectral densities is recovered as upper limit. Starting from special distributions of coherent states as external reservoir, the exact time evolution, described through Fox H-functions, shows long time inverse power law decays, departing from the exponential-like relaxations obtained for the Drude model. Different from the weak coupling regime, in the sub-ohmic condition, undamped oscillations plus inverse power law relaxations appear in the long time evolution of the observables position and momentum. Under the same condition, the number of excitations shows trapping of the population of the excited levels and oscillations enveloped in inverse power law relaxations. Similarly to the weak coupling regime, critical configurations give arbitrarily slow relaxations useful for the control of the dynamics. If compared to the value obtained in weak coupling condition, for strong couplings the critical frequency is enhanced by a factor 4.

scholarly journals Transverse magneto-optical Kerr effect at narrow optical resonances

Nanophotonics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 287-296 ◽  
Author(s):  
Olga V. Borovkova ◽  
Felix Spitzer ◽  
Vladimir I. Belotelov ◽  
Ilya A. Akimov ◽  
Alexander N. Poddubny ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Kerr Effect ◽  
Weak Coupling ◽  
Diluted Magnetic Semiconductor ◽  
Zeeman Splitting ◽  
Optical Kerr Effect ◽  
Strong Coupling Regime ◽  
Weak Coupling Regime ◽  
Optical Resonances ◽  
Magneto Optical Kerr Effect

AbstractMagneto-optical spectroscopy based on the transverse magneto-optical Kerr effect (TMOKE) is a sensitive method for investigating magnetically-ordered media. Previous studies were limited to the weak coupling regime where the spectral width of optical transitions considerably exceeded the Zeeman splitting in magnetic field. Here, we investigate experimentally and theoretically the transverse Kerr effect in the vicinity of comparatively narrow optical resonances in confined quantum systems. For experimental demonstration we studied the ground-state exciton resonance in a (Cd,Mn)Te diluted magnetic semiconductor quantum well, for which the strong exchange interaction with magnetic ions leads to giant Zeeman splitting of exciton spin states. For low magnetic fields in the weak coupling regime, the Kerr effect magnitude grows linearly with increasing Zeeman splitting showing a dispersive S-shaped spectrum, which remains almost unchanged in this range. For large magnetic fields in the strong coupling regime, the magnitude saturates, whereas the spectrum becomes strongly modified by the appearance of two separate peaks. TMOKE is sensitive not only to the sample surface but can also be used to probe in detail the confined electronic states in buried nanostructures if their capping layer is sufficiently transparent.

Semiconductor microcavity under magnetic field: From the weak coupling to the strong coupling regime

1996 ◽  
Vol 40 (1-8) ◽  
pp. 497-500 ◽  
Author(s):  
J Tignon ◽  
P Voisin ◽  
J Wainstain ◽  
C Delalande ◽  
M Voos ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Strong Coupling ◽  
Weak Coupling ◽  
Strong Coupling Regime ◽  
Semiconductor Microcavity

Crossover from the strong-coupling to the weak-coupling regime in the SU(2)-symmetric Thirring model

1983 ◽  
Vol 94 (6-7) ◽  
pp. 254-258 ◽  
Author(s):  
G.I. Japaridze ◽  
A.A. Nersesyan ◽  
P.B. Wiegmann
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Thirring Model ◽  
Weak Coupling Regime

scholarly journals Bound states in the continuum in strong-coupling and weak-coupling regimes under the cylinder – ring transition

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nikolay Solodovchenko ◽  
Kirill Samusev ◽  
Daria Bochek ◽  
Mikhail Limonov
Keyword(s):  
Strong Coupling ◽  
Weak Coupling ◽  
Bound States ◽  
Dielectric Cylinder ◽  
Weak Coupling Regime ◽  
Field Zone ◽  
The Past ◽  
Resonant Modes ◽  
Avoided Crossing ◽  
The Continuum

Abstract Bound states in the continuum (BIC) have been at the forefront of research in optics and photonics over the past decade. It is of great interest to study the effects associated with quasi-BICs in the simplest structures, where quasi-BICs are very pronounced. An example is a dielectric cylinder, and in a number of works, quasi-BICs have been studied both in single cylinders and in structures composed of cylinders. In this work, we studied the properties of quasi-BICs during the transition from a homogeneous dielectric cylinder in an air environment to a ring with narrow walls while increasing the diameter of the inner air cylinder gradually. The results demonstrate the quasi-BIC crossover from the strong-coupling to the weak-coupling regime, which manifests itself in the transition from the avoided crossing of branches to their intersection with the quasi-BIC being preserved on only one straight branch. In the regime of strong-coupling and quasi-BIC, three waves interfere in the far-field zone: two waves corresponding to the resonant modes of the structure and the wave scattered by the structure as a whole. The validity of the Fano resonance concept is discussed since it describes the interference of only two waves under weak coupling conditions.

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