scholarly journals Modified Scaled Hierarchical Equation of Motion Approach for the Study of Quantum Coherence in Photosynthetic Complexes

2011 ◽  
Vol 115 (6) ◽  
pp. 1531-1537 ◽  
Author(s):  
Jing Zhu ◽  
Sabre Kais ◽  
Patrick Rebentrost ◽  
Alán Aspuru-Guzik
Keyword(s):  
Quantum Coherence ◽  
Equation Of Motion ◽  
Photosynthetic Complexes

Long-lived quantum coherence and non-Markovianity of photosynthetic complexes

2014 ◽  
Vol 89 (4) ◽  
Author(s):  
Hong-Bin Chen ◽  
Jiun-Yi Lien ◽  
Chi-Chuan Hwang ◽  
Yueh-Nan Chen
Keyword(s):  
Quantum Coherence ◽  
Photosynthetic Complexes

scholarly journals Do photosynthetic complexes use quantum coherence to increase their efficiency? Probably not

2021 ◽  
Vol 7 (8) ◽  
pp. eabc4631
Author(s):  
Elinor Zerah Harush ◽  
Yonatan Dubi
Keyword(s):  
Quantum Coherence ◽  
Systems Approach ◽  
Open Quantum Systems ◽  
Structural Parameters ◽  
Quantum Systems ◽  
Direct Evaluation ◽  
Substantial Role ◽  
Physiological Conditions ◽  
Photosynthetic Complexes ◽  
Series Of Experiments

Answering the titular question has become a central motivation in the field of quantum biology, ever since the idea was raised following a series of experiments demonstrating wave-like behavior in photosynthetic complexes. Here, we report a direct evaluation of the effect of quantum coherence on the efficiency of three natural complexes. An open quantum systems approach allows us to simultaneously identify their level of “quantumness” and efficiency, under natural physiological conditions. We show that these systems reside in a mixed quantum-classical regime, characterized by dephasing-assisted transport. Yet, we find that the change in efficiency at this regime is minute at best, implying that the presence of quantum coherence does not play a substantial role in enhancing efficiency. However, in this regime, efficiency is independent of any structural parameters, suggesting that evolution may have driven natural complexes to their parameter regime to “design” their structure for other uses.

scholarly journals Coherence and decoherence in biological systems: principles of noise-assisted transport and the origin of long-lived coherences

2012 ◽  
Vol 370 (1972) ◽  
pp. 3638-3657 ◽  
Author(s):  
A. W. Chin ◽  
S. F. Huelga ◽  
M. B. Plenio
Keyword(s):  
Quantum Dynamics ◽  
Functional Role ◽  
Quantum Coherence ◽  
Biological Systems ◽  
Optimal Operation ◽  
Noisy Environments ◽  
Transport Networks ◽  
Natural Conditions ◽  
Light Harvesting Complex ◽  
Photosynthetic Complexes

The quantum dynamics of transport networks in the presence of noisy environments has recently received renewed attention with the discovery of long-lived coherences in different photosynthetic complexes. This experimental evidence has raised two fundamental questions: firstly, what are the mechanisms supporting long-lived coherences; and, secondly, how can we assess the possible functional role that the interplay of noise and quantum coherence might play in the seemingly optimal operation of biological systems under natural conditions? Here, we review recent results, illuminate them by means of two paradigmatic systems (the Fenna–Matthew–Olson complex and the light-harvesting complex LHII) and present new progress on both questions.

Quantum coherence in photosynthetic complexes

2011 ◽  
Vol 248 (4) ◽  
pp. 833-838 ◽  
Author(s):  
Tessa R. Calhoun ◽  
Graham R. Fleming
Keyword(s):  
Quantum Coherence ◽  
Photosynthetic Complexes

scholarly journals Long-lived quantum coherence in photosynthetic complexes at physiological temperature

2010 ◽  
Vol 107 (29) ◽  
pp. 12766-12770 ◽  
Author(s):  
G. Panitchayangkoon ◽  
D. Hayes ◽  
K. A. Fransted ◽  
J. R. Caram ◽  
E. Harel ◽  
...  
Keyword(s):  
Quantum Coherence ◽  
Physiological Temperature ◽  
Photosynthetic Complexes

Particle motion with air resistance

2012 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Gy. Sitkei
Keyword(s):  
Basic Equation ◽  
Initial Conditions ◽  
Equation Of Motion ◽  
Terminal Velocity ◽  
Dimensionless Form ◽  
Wood Industry ◽  
Acceptable Error ◽  
General Validity ◽  
Practical Applications ◽  
Air Resistance

Motion of particles with air resistance (e.g. horizontal and inclined throwing) plays an important role in many technological processes in agriculture, wood industry and several other fields. Although, the basic equation of motion of this problem is well known, however, the solutions for practical applications are not sufficient. In this article working diagrams were developed for quick estimation of the throwing distance and the terminal velocity. Approximate solution procedures are presented in closed form with acceptable error. The working diagrams provide with arbitrary initial conditions in dimensionless form of general validity.

Finite difference code for velocity and surface traction of a Fluid between Two Eccentric Spheres

2015 ◽  
Vol 11 (1) ◽  
pp. 2960-2971
Author(s):  
M.Abdel Wahab
Keyword(s):  
Velocity Field ◽  
Angular Velocity ◽  
Finite Difference ◽  
Numerical Study ◽  
Outer Sphere ◽  
Equation Of Motion ◽  
Annular Region ◽  
Surface Traction ◽  
Angular Velocities ◽  
Axis Passing

The Numerical study of the flow of a fluid in the annular region between two eccentric sphere susing PHP Code isinvestigated. This flow is created by considering the inner sphere to rotate with angular velocity 1  and the outer sphererotate with angular velocity 2  about the axis passing through their centers, the z-axis, using the three dimensionalBispherical coordinates (, ,) .The velocity field of fluid is determined by solving equation of motion using PHP Codeat different cases of angular velocities of inner and outer sphere. Also Finite difference code is used to calculate surfacetractions at outer sphere.

On the Harmonic Oscillations for the Motion of a Dynamical System

2017 ◽  
Vol 13 (2) ◽  
pp. 4657-4670
Author(s):  
W. S. Amer
Keyword(s):  
Dynamical System ◽  
Numerical Solutions ◽  
Equation Of Motion ◽  
Parameter Method ◽  
Kutta Method ◽  
Small Parameter Method ◽  
Harmonic Oscillations ◽  
Pivot Point ◽  
Runge Kutta Method ◽  
High Consistency

This work touches two important cases for the motion of a pendulum called Sub and Ultra-harmonic cases. The small parameter method is used to obtain the approximate analytic periodic solutions of the equation of motion when the pivot point of the pendulum moves in an elliptic path. Moreover, the fourth order Runge-Kutta method is used to investigate the numerical solutions of the considered model. The comparison between both the analytical solution and the numerical ones shows high consistency between them.

A Multi-Layer Approach to the Equation of Motion Coupled-Cluster Method for the Electron Affinity

2020 ◽  
Author(s):  
Soumi Haldar ◽  
Achintya Kumar Dutta
Keyword(s):  
Electron Affinity ◽  
Electron Attachment ◽  
Equation Of Motion ◽  
Cluster Method ◽  
Coupled Cluster ◽  
Coupled Cluster Method ◽  
Large Molecules ◽  
Layer Method ◽  
Speed Up ◽  
Attachment Process

We have presented a multi-layer implementation of the equation of motion coupled-cluster method for the electron affinity, based on local and pair natural orbitals. The method gives consistent accuracy for both localized and delocalized anionic states. It results in many fold speedup in computational timing as compared to the canonical and DLPNO based implementation of the EA-EOM-CCSD method. We have also developed an explicit fragment-based approach which can lead to even higher speed-up with little loss in accuracy. The multi-layer method can be used to treat the environmental effect of both bonded and non-bonded nature on the electron attachment process in large molecules.<br>

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