scholarly journals Quantum evolution of entanglement property in two-qubit and oscillator coupling system

2012 ◽  
Vol 61 (1) ◽  
pp. 014208
Author(s):  
Xia Jian-Ping ◽  
Ren Xue-Zao ◽  
Cong Hong-Lu ◽  
Wang Xu-Wen ◽  
He Shu
Author(s):  
William J. Dougherty ◽  
Samuel S. Spicer

In recent years, considerable attention has focused on the morphological nature of the excitation-contraction coupling system of striated muscle. Since the study of Porter and Palade, it has become evident that the sarcoplastic reticulum (SR) and transverse tubules constitute the major elements of this system. The problem still exists, however, of determining the mechamisms by which the signal to interdigitate is presented to the thick and thin myofilaments. This problem appears to center on the movement of Ca++ions between myofilaments and SR. Recently, Philpott and Goldstein reported acid mucosubstance associated with the SR of fish branchial muscle using the colloidal thorium dioxide technique, and suggested that this material may serve to bind or release divalent cations such as Ca++. In the present study, Hale's iron solution adapted to electron microscopy was applied to formalin-fixed myofibrils isolated from glycerol-extracted rabbit psoas muscles and to frozen sections of formalin-fixed rat psoas muscles.


1999 ◽  
Vol 96 (12) ◽  
pp. 1739-1744 ◽  
Author(s):  
T. S. UNTIDT, S. J. GLASER, C. GRIESIN

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3400
Author(s):  
Jie Xing ◽  
Peng Wu

Bidirectional coupling systems for electricity and natural gas composed of gas units and power-to-gas (P2G) facilities improve the interactions between different energy systems. In this paper, a combined optimization planning method for an electricity-natural gas coupling system with P2G was studied. Firstly, the characteristics of the component model of the electricity-natural gas coupling system were analyzed. The optimization planning model for the electricity-natural gas coupling system was established with the goal of minimizing the sum of the annual investment costs and the annual operation costs. Based on the established model, the construction statuses for different types of units, power lines, and pipelines and the output distribution values for gas units and P2G stations were optimized. Then, the immune algorithm was proposed to solve the optimization planning model. Finally, an electricity-natural gas coupling system composed of a seven-node natural gas system and a nine-node power system was taken as an example to verify the rationality and effectiveness of the model under different scenarios.


2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Daniel Burgarth ◽  
Paolo Facchi ◽  
Hiromichi Nakazato ◽  
Saverio Pascazio ◽  
Kazuya Yuasa
Keyword(s):  

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 773
Author(s):  
Danko D. Georgiev

Identifying the physiological processes in the central nervous system that underlie our conscious experiences has been at the forefront of cognitive neuroscience. While the principles of classical physics were long found to be unaccommodating for a causally effective consciousness, the inherent indeterminism of quantum physics, together with its characteristic dichotomy between quantum states and quantum observables, provides a fertile ground for the physical modeling of consciousness. Here, we utilize the Schrödinger equation, together with the Planck–Einstein relation between energy and frequency, in order to determine the appropriate quantum dynamical timescale of conscious processes. Furthermore, with the help of a simple two-qubit toy model we illustrate the importance of non-zero interaction Hamiltonian for the generation of quantum entanglement and manifestation of observable correlations between different measurement outcomes. Employing a quantitative measure of entanglement based on Schmidt decomposition, we show that quantum evolution governed only by internal Hamiltonians for the individual quantum subsystems preserves quantum coherence of separable initial quantum states, but eliminates the possibility of any interaction and quantum entanglement. The presence of non-zero interaction Hamiltonian, however, allows for decoherence of the individual quantum subsystems along with their mutual interaction and quantum entanglement. The presented results show that quantum coherence of individual subsystems cannot be used for cognitive binding because it is a physical mechanism that leads to separability and non-interaction. In contrast, quantum interactions with their associated decoherence of individual subsystems are instrumental for dynamical changes in the quantum entanglement of the composite quantum state vector and manifested correlations of different observable outcomes. Thus, fast decoherence timescales could assist cognitive binding through quantum entanglement across extensive neural networks in the brain cortex.


2021 ◽  
Vol 3 (2) ◽  
pp. 262-271
Author(s):  
Pablo Reséndiz-Vázquez ◽  
Ricardo Román-Ancheyta ◽  
Roberto León-Montiel

Transport phenomena in photosynthetic systems have attracted a great deal of attention due to their potential role in devising novel photovoltaic materials. In particular, energy transport in light-harvesting complexes is considered quite efficient due to the balance between coherent quantum evolution and decoherence, a phenomenon coined Environment-Assisted Quantum Transport (ENAQT). Although this effect has been extensively studied, its behavior is typically described in terms of the decoherence’s strength, namely weak, moderate or strong. Here, we study the ENAQT in terms of quantum correlations that go beyond entanglement. Using a subsystem of the Fenna–Matthews–Olson complex, we find that discord-like correlations maximize when the subsystem’s transport efficiency increases, while the entanglement between sites vanishes. Our results suggest that quantum discord is a manifestation of the ENAQT and highlight the importance of beyond-entanglement correlations in photosynthetic energy transport processes.


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