scholarly journals Demonstration of quantum synchronization based on second-order quantum coherence of entangled photons

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Runai Quan ◽  
Yiwei Zhai ◽  
Mengmeng Wang ◽  
Feiyan Hou ◽  
Shaofeng Wang ◽  
...  
Keyword(s):  
Quantum Coherence ◽  
Second Order ◽  
Entangled Photons ◽  
Quantum Synchronization

Realization of Sub-picosecond Clock Synchronization based on Second-Order Quantum Coherence

CLEO: 2015 ◽  
2015 ◽  
Author(s):  
Runai Quan ◽  
Ruifang Dong ◽  
Yiwei Zhai ◽  
Mengmeng Wang ◽  
Shaofeng Wang ◽  
...  
Keyword(s):  
Quantum Coherence ◽  
Clock Synchronization ◽  
Second Order

scholarly journals Quantum coherence of cosmological perturbations

2017 ◽  
Vol 32 (35) ◽  
pp. 1750191 ◽  
Author(s):  
Massimo Giovannini
Keyword(s):  
Quantum Coherence ◽  
Large Scale ◽  
Optical Cavity ◽  
Single Mode ◽  
Second Order ◽  
Cosmological Perturbations ◽  
Single Mode Approximation ◽  
Optical Limit ◽  
Zero Time ◽  
Scale Limit

In this paper, the degrees of quantum coherence of cosmological perturbations of different spins are computed in the large-scale limit and compared with the standard results holding for a single mode of the electromagnetic field in an optical cavity. The degree of second-order coherence of curvature inhomogeneities (and, more generally, of the scalar modes of the geometry) reproduces faithfully the optical limit. For the vector and tensor fluctuations, the numerical values of the normalized degrees of second-order coherence in the zero time-delay limit are always larger than unity (which is the Poisson benchmark value) but differ from the corresponding expressions obtainable in the framework of the single-mode approximation. General lessons are drawn on the quantum coherence of large-scale cosmological fluctuations.

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

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