Vibrational potentials of the low frequency out‐of‐plane motion in the ground and excited singlet electronic states of 9,10‐dihydrophenanthrene

1992 ◽  
Vol 96 (10) ◽  
pp. 7229-7236 ◽  
Author(s):  
Marek Z. Zgierski ◽  
Francesco Zerbetto ◽  
Young‐Dong Shin ◽  
Edward C. Lim
Keyword(s):  
Low Frequency ◽  
Electronic States ◽  
Plane Motion ◽  
Excited Singlet ◽  
Out Of Plane

A Strain Distribution Based Classification of Ortho-Planar Springs: An Outlook to Piezoelectric Applications

2016 ◽  
Author(s):  
R. B. van Kempen ◽  
J. L. Herder ◽  
N. Tolou
Keyword(s):  
Strain Distribution ◽  
Low Frequency ◽  
Plane Motion ◽  
Piezoelectric Energy Harvesting ◽  
Piezoelectric Energy ◽  
Planar Shape ◽  
Bending Mode ◽  
Frequency Transducer ◽  
Out Of Plane

Ortho-planar springs are characterized by their planar shape and the dominant out of plane motion. These springs have benefits for integration in piezoelectric energy harvesting transducers, because of their compactness and monolithic planar manufacturing. The operating behavior in the first low frequency bending mode can be optimized by obtaining an appropriate strain distribution. A holistic design approach is proposed that contains both the focus on strain distribution as on the low frequency dynamic operation challenge. Therefore a classification based on the strain distribution has been made, which is derived from the perspective of loading, clamping and geometry of single flexures of ortho-planar springs. A comparison based on the type of strain (bending/torsion ratio), strain inversion,off-axis stiffness and the natural frequency-normalized area factor (NFNA) has been performed. The double clamped folded configuration shows the most potential for future optimal low frequency transducer designs.

scholarly journals Quantum Simulations of Charge Separation at a Model Donor-Acceptor Interface: Role of Delocalization and Local Packing

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Allen Kelley ◽  
Kush Patel ◽  
Eric R. Bittner
Keyword(s):  
Excited States ◽  
Degrees Of Freedom ◽  
Mean Field ◽  
Low Frequency ◽  
Acid Methyl Ester ◽  
Electronic States ◽  
Organic Polymer ◽  
Donor And Acceptor ◽  
Out Of Plane ◽  
Donor Acceptor

Organic Polymer-based photovoltaic systems offer a viable alternative to more standard solid-state devices for light-harvesting applications. In this study, we investigate the electronic dynamics of a model organic photovoltaic (OPV) heterojunction consisting of polyphenylene vinylene (PPV) oligomers and a [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend. Our approach treats the classical molecular dynamics of the atoms within an Ehrenfest mean-field treatment of the π-π⁎ singly excited states spanning a subset of donor and acceptor molecules near the phase boundary of the blend. Our results indicate that interfacial electronic states are modulated by C=C bond stretching motions and that such motions induce avoided crossings between nearby excited states thereby facilitating transitions from localized excitonic configurations to delocalized charge-separated configurations on an ultrafast time-scale. The lowest few excited states of the model interface rapidly mix allowing low frequency C-C out-of-plane torsions to modulate the potential energy surface such that the system can sample both intermolecular charge-transfer and charge-separated electronic configurations on sub-100 fs time scales. Our simulations support an emerging picture of carrier generation in OPV systems in which interfacial electronic states can rapidly decay into charge-separated and current producing states via coupling to vibronic degrees of freedom.

scholarly journals Non-linear Terahertz driving of plasma waves in layered cuprates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Gabriele ◽  
Mattia Udina ◽  
Lara Benfatto
Keyword(s):  
Low Frequency ◽  
Plasma Waves ◽  
Meissner Effect ◽  
High Energy ◽  
Plasma Mode ◽  
Light Pulses ◽  
High Frequency Plasma ◽  
Non Linear ◽  
Out Of Plane ◽  
Layered Cuprates

AbstractThe hallmark of superconductivity is the rigidity of the quantum-mechanical phase of electrons, responsible for superfluid behavior and Meissner effect. The strength of the phase stiffness is set by the Josephson coupling, which is strongly anisotropic in layered cuprates. So far, THz light pulses have been used to achieve non-linear control of the out-of-plane Josephson plasma mode, whose frequency lies in the THz range. However, the high-energy in-plane plasma mode has been considered insensitive to THz pumping. Here, we show that THz driving of both low-frequency and high-frequency plasma waves is possible via a general two-plasmon excitation mechanism. The anisotropy of the Josephson couplings leads to markedly different thermal effects for the out-of-plane and in-plane response, linking in both cases the emergence of non-linear photonics across Tc to the superfluid stiffness. Our results show that THz light pulses represent a preferential knob to selectively drive phase excitations in unconventional superconductors.

Out-of-Plane Motion Effects in Microscopic Particle Image Velocimetry

2003 ◽  
Vol 125 (5) ◽  
pp. 895-901 ◽  
Author(s):  
Michael G. Olsen ◽  
Chris J. Bourdon
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Laser Sheet ◽  
Plane Motion ◽  
Entire Volume ◽  
Measurement Volume ◽  
Microscopic Particle ◽  
Image Velocimetry ◽  
Out Of Plane ◽  
Signal Peak

In microscopic particle image velocimetry (microPIV) experiments, the entire volume of a flowfield is illuminated, resulting in all of the particles in the field of view contributing to the image. Unlike in light-sheet PIV, where the depth of the measurement volume is simply the thickness of the laser sheet, in microPIV, the measurement volume depth is a function of the image forming optics of the microscope. In a flowfield with out-of-plane motion, the measurement volume (called the depth of correlation) is also a function of the magnitude of the out-of-plane motion within the measurement volume. Equations are presented describing the depth of correlation and its dependence on out-of-plane motion. The consequences of this dependence and suggestions for limiting its significance are also presented. Another result of the out-of-plane motion is that the height of the PIV signal peak in the correlation plane will decrease. Because the height of the noise peaks will not be affected by the out-of-plane motion, this could lead to erroneous velocity measurements. An equation is introduced that describes the effect of the out-of-plane motion on the signal peak height, and its implications are discussed. Finally, the derived analytical equations are compared to results calculated using synthetic PIV images, and the agreement between the two is seen to be excellent.

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