scholarly journals Nonadiabatic modal dynamics around a third-order Exceptional Point in a planar waveguide

2021 ◽  
Vol 483 ◽  
pp. 126644
Author(s):  
Sibnath Dey ◽  
Arnab Laha ◽  
Somnath Ghosh
Keyword(s):  
Planar Waveguide ◽  
Exceptional Point ◽  
Third Order ◽  
Modal Dynamics

scholarly journals PT -symmetric waveguide system with evidence of a third-order exceptional point

2017 ◽  
Vol 95 (5) ◽  
Author(s):  
Jan Schnabel ◽  
Holger Cartarius ◽  
Jörg Main ◽  
Günter Wunner ◽  
Walter Dieter Heiss
Keyword(s):  
Exceptional Point ◽  
Third Order ◽  
Waveguide System

scholarly journals Third-order exceptional point and successive switching among three states in an optical microcavity

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
Arnab Laha ◽  
Dinesh Beniwal ◽  
Sibnath Dey ◽  
Abhijit Biswas ◽  
Somnath Ghosh
Keyword(s):  
Exceptional Point ◽  
Third Order ◽  
Optical Microcavity

scholarly journals SIMPLE MODELS OF THREE COUPLED PT -SYMMETRIC WAVE GUIDES ALLOWING FOR THIRD-ORDER EXCEPTIONAL POINTS

2017 ◽  
Vol 57 (6) ◽  
pp. 454 ◽  
Author(s):  
Jan Schnabel ◽  
Holger Cartarius ◽  
Jörg Main ◽  
Günter Wunner ◽  
Walter Dieter Heiss
Keyword(s):  
Matrix Model ◽  
Theoretical Models ◽  
Exceptional Point ◽  
Third Order ◽  
Exceptional Points ◽  
Symmetric Wave ◽  
Wave Guides ◽  
Delta Functions ◽  
Idealised Model ◽  
Parameter Ranges

We study theoretical models of three coupled wave guides with a <em>PT</em>-symmetric distribution of gain and loss. A realistic matrix model is developed in terms of a three-mode expansion. By comparing with a previously postulated matrix model it is shown how parameter ranges with good prospects of finding a third-order exceptional point (EP3) in an experimentally feasible arrangement of semiconductors can be determined. In addition it is demonstrated that continuous distributions of exceptional points, which render the discovery of the EP3 difficult, are not only a feature of extended wave guides but appear also in an idealised model of infinitely thin guides shaped by delta functions.

scholarly journals Detecting deformed commutators with exceptional points in optomechanical sensors

2021 ◽  
Author(s):  
Dianzhen Cui ◽  
Tao Li ◽  
Jianning Li ◽  
Xuexi Yi
Keyword(s):  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
The Other ◽  
Exceptional Point ◽  
Weak Effect ◽  
Third Order ◽  
Exceptional Points ◽  
The One ◽  
Gravity Perturbation ◽  
Canonical Position

Abstract Models of quantum gravity imply a modification of the canonical position-momentum commutation relations. In this manuscript, working with a binary mechanical system, we examine the effect of quantum gravity on the exceptional points of the system. On the one side, we find that the exceedingly weak effect of quantum gravity can be sensed via pushing the system towards a second-order exceptional point, where the spectra of the non-Hermitian system exhibits non-analytic and even discontinuous behavior. On the other side, the gravity perturbation will affect the sensitivity of the system to deposition mass. In order to further enhance the sensitivity of the system to quantum gravity, we extend the system to the other one which has a third-order exceptional point. Our work provides a feasible way to use exceptional points as a new tool to explore the effect of quantum gravity.

Probe size and 5th-order aberration

1987 ◽  
Vol 45 ◽  
pp. 134-135 ◽  
Author(s):  
Zhifeng Shao
Keyword(s):  
Electron Probe ◽  
Spherical Aberration ◽  
Wave Length ◽  
Cylindrical Symmetry ◽  
Electron Wave ◽  
Third Order ◽  
The Third ◽  
Probe Radius ◽  
Small Probe ◽  
Probe Size

A small electron probe has many applications in many fields and in the case of the STEM, the probe size essentially determines the ultimate resolution. However, there are many difficulties in obtaining a very small probe.Spherical aberration is one of them and all existing probe forming systems have non-zero spherical aberration. The ultimate probe radius is given byδ = 0.43Csl/4ƛ3/4where ƛ is the electron wave length and it is apparent that δ decreases only slowly with decreasing Cs. Scherzer pointed out that the third order aberration coefficient always has the same sign regardless of the field distribution, provided only that the fields have cylindrical symmetry, are independent of time and no space charge is present. To overcome this problem, he proposed a corrector consisting of octupoles and quadrupoles.

Children’s Recall of Approximations to English

1973 ◽  
Vol 16 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Elizabeth Carrow ◽  
Michael Mauldin
Keyword(s):  
Language Development ◽  
Fourth Order ◽  
Third Order ◽  
Memory Processes ◽  
The Third ◽  
General Index ◽  
General Linguistic

As a general index of language development, the recall of first through fourth order approximations to English was examined in four, five, six, and seven year olds and adults. Data suggested that recall improved with age, and increases in approximation to English were accompanied by increases in recall for six and seven year olds and adults. Recall improved for four and five year olds through the third order but declined at the fourth. The latter finding was attributed to deficits in semantic structures and memory processes in four and five year olds. The former finding was interpreted as an index of the development of general linguistic processes.

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