scholarly journals Generation and dynamics of entangled fermion–photon–phonon states in nanocavities

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 491-511 ◽  
Author(s):  
Mikhail Tokman ◽  
Maria Erukhimova ◽  
Yongrui Wang ◽  
Qianfan Chen ◽  
Alexey Belyanin
Keyword(s):  
Emission Spectra ◽  
Coupled System ◽  
Vibrational Modes ◽  
Tripartite Entanglement ◽  
Quantum Emitter ◽  
Parametric Resonances ◽  
Analytic Expressions ◽  
Entangled Quantum States ◽  
Formation And Evolution ◽  
Quantum Optomechanics

AbstractWe develop the analytic theory describing the formation and evolution of entangled quantum states for a fermionic quantum emitter coupled simultaneously to a quantized electromagnetic field in a nanocavity and quantized phonon or mechanical vibrational modes. The theory is applicable to a broad range of cavity quantum optomechanics problems and emerging research on plasmonic nanocavities coupled to single molecules and other quantum emitters. The optimal conditions for a tripartite entanglement are realized near the parametric resonances in a coupled system. The model includes dissipation and decoherence effects due to coupling of the fermion, photon, and phonon subsystems to their dissipative reservoirs within the stochastic evolution approach, which is derived from the Heisenberg–Langevin formalism. Our theory provides analytic expressions for the time evolution of the quantum state and observables and the emission spectra. The limit of a classical acoustic pumping and the interplay between parametric and standard one-photon resonances are analyzed.

DFT/TDDFT investigation on the UV-vis absorption and fluorescence properties of alizarin dye

2015 ◽  
Vol 17 (9) ◽  
pp. 6374-6382 ◽  
Author(s):  
Anna Amat ◽  
Costanza Miliani ◽  
Aldo Romani ◽  
Simona Fantacci
Keyword(s):  
Potential Energy ◽  
Potential Energy Curve ◽  
Emission Spectra ◽  
Fluorescence Properties ◽  
Energy Curve ◽  
Vibrational Modes

Potential energy curve for the ESIPT. Top inset: vibrationally resolved emission spectra computed for both tautomers. Bottom insets: main vibrational modes.

Analytical Study of Dispersion of Stress Waves in a Weakly Coupled Layered System

1995 ◽  
Author(s):  
A. F. Vakakis ◽  
C. Cetinkaya
Keyword(s):  
Practical Importance ◽  
Coupled System ◽  
Stress Waves ◽  
Layered System ◽  
Convolution Integrals ◽  
Weakly Coupled ◽  
Weakly Coupled System ◽  
Analytic Expressions ◽  
Convolution Kernels ◽  
As Stress

Abstract Dispersion of transient stress waves in the first layer of a weakly coupled semi-infinite bi-layered system is carried out. Fourier transform inversions are performed analytically by making use of the fact that the weakly coupled system possesses small propagation zones (PZs) in the frequency domain. Low- and high-frequency asymptotic approximations to the transient waves are computed, taking into account frequency components of the transfer function in the first and second PZs, respectively. The derived analytic expressions are superpositions of non-oscillating terms and convolution integrals with decaying oscillatory kernels. Depending on the frequency and the amplitude of the convolution kernels, the dispersed waves overshoot or undershoot the applied impulsive excitation. This result is of significant practical importance in the design of layered systems as stress attenuators.

scholarly journals Residual Predictive Information Flow in the Tight Coupling Limit: Analytic Insights from a Minimalistic Model

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1010
Author(s):  
Benjamin Wahl ◽  
Ulrike Feudel ◽  
Jaroslav Hlinka ◽  
Matthias Wächter ◽  
Joachim Peinke ◽  
...  
Keyword(s):  
Information Flow ◽  
Coupling Strength ◽  
Social Groups ◽  
Coupled System ◽  
Model Description ◽  
Causal Connection ◽  
Noise Strength ◽  
Tight Coupling ◽  
Predictive Information ◽  
Analytic Expressions

In a coupled system, predictive information flows from the causing to the caused variable. The amount of transferred predictive information can be quantified through the use of transfer entropy or, for Gaussian variables, equivalently via Granger causality. It is natural to expect and has been repeatedly observed that a tight coupling does not permit to reconstruct a causal connection between causing and caused variables. Here, we show that for a model of interacting social groups, carried from the master equation to the Fokker–Planck level, a residual predictive information flow can remain for a pair of uni-directionally coupled variables even in the limit of infinite coupling strength. We trace this phenomenon back to the question of how the synchronizing force and the noise strength scale with the coupling strength. A simplified model description allows us to derive analytic expressions that fully elucidate the interplay between deterministic and stochastic model parts.

scholarly journals Modeling the infrared cascade spectra of small PAHs: the 11.2 μm band

2021 ◽  
Vol 140 (9) ◽  
Author(s):  
Cameron J. Mackie ◽  
Alessandra Candian ◽  
Timothy J. Lee ◽  
Alexander G. G. M. Tielens
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Rotational Temperature ◽  
Emission Spectra ◽  
Vibrational Modes ◽  
Vibrational States ◽  
Blue Wing ◽  
Polycyclic Aromatic ◽  
Cascade Emission ◽  
Red Wing

AbstractThe profile of the 11.2 μm feature of the infrared (IR) cascade emission spectra of polycyclic aromatic hydrocarbon (PAH) molecules is investigated using a vibrational anharmonic method. Several factors are found to affect the profile including: the energy of the initially absorbed ultraviolet (UV) photon, the density of vibrational states, the anharmonic nature of the vibrational modes, the relative intensities of the vibrational modes, the rotational temperature of the molecule, and blending with nearby features. Each of these factors is explored independently and influence either the red or blue wing of the 11.2 μm feature. The majority impact solely the red wing, with the only factor altering the blue wing being the rotational temperature.

scholarly journals GHZ-like states in the Qubit-Qudit Rabi model

2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Yuan Shen ◽  
Giampiero Marchegiani ◽  
Gianluigi Catelani ◽  
Luigi Amico ◽  
Ai Qun Liu ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Coupled System ◽  
Relevant Information ◽  
Tripartite Entanglement ◽  
Bipartite Entanglement ◽  
Strongly Coupled ◽  
Future Studies ◽  
Adiabatic Switching ◽  
State Transfer ◽  
Rabi Model

We study a Rabi type Hamiltonian system in which a qubit and a dd-level quantum system (qudit) are coupled through a common resonator. In the weak and strong coupling limits the spectrum is analysed through suitable perturbative schemes. The analysis show that the presence of the multilevels of the qudit effectively enhance the qubit-qudit interaction. The ground state of the strongly coupled system is found to be of Greenberger-Horne-Zeilinger (GHZ) type. Therefore, despite the qubit-qudit strong coupling, the nature of the specific tripartite entanglement of the GHZ state suppresses the bipartite entanglement. We analyze the system dynamics under quenching and adiabatic switching of the qubit-resonator and qudit-resonator couplings. In the quench case, we found that the non-adiabatic generation of photons in the resonator is enhanced by the number of levels in the qudit. The adiabatic control represents a possible route for preparation of GHZ states. Our analysis provides relevant information for future studies on coherent state transfer in qubit-qudit systems.

AFM study of the dynamics of α-alumina surface faceting during high-temperature processing

1995 ◽  
Vol 53 ◽  
pp. 334-335 ◽  
Author(s):  
Michael W. Bench ◽  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
High Temperature ◽  
Thin Foil ◽  
Sem Analysis ◽  
Conductive Coatings ◽  
Force Microscopy ◽  
Minimal Sample ◽  
Atomic Force ◽  
Formation And Evolution ◽  
High Temperature Processing ◽  
Nominal Surface

To gain a better understanding of the surface faceting that occurs in α-alumina during high temperature processing, atomic force microscopy (AFM) studies have been performed to follow the formation and evolution of the facets. AFM was chosen because it allows for analysis of topographical details down to the atomic level with minimal sample preparation. This is in contrast to SEM analysis, which typically requires the application of conductive coatings that can alter the surface between subsequent heat treatments. Similar experiments have been performed in the TEM; however, due to thin foil and hole edge effects the results may not be representative of the behavior of bulk surfaces.The AFM studies were performed on a Digital Instruments Nanoscope III using microfabricated Si3N4 cantilevers. All images were recorded in air with a nominal applied force of 10-15 nN. The alumina samples were prepared from pre-polished single crystals with (0001), , and nominal surface orientations.

Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

1994 ◽  
Vol 52 ◽  
pp. 728-729
Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  
Keyword(s):  
High Pressure ◽  
High Resolution ◽  
Atomic Structure ◽  
Emission Spectra ◽  
High Resolution Electron Microscopy ◽  
Planar Defects ◽  
X Ray ◽  
Infinite Layer ◽  
Resolution Electron ◽  
Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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