Mapping the spin angular momentum distribution offocused linearly and circularly polarized vortex fields

2021 ◽  
Author(s):  
Xiaojin Yin ◽  
Chen Yang ◽  
Jinhong Li ◽  
Yakai Zhang ◽  
Chungang Zhao
Keyword(s):  
Angular Momentum ◽  
Momentum Distribution ◽  
Spin Angular Momentum ◽  
Circularly Polarized

scholarly journals Inversion of the longitudinal component of spin angular momentum in the focus of a left-handed circularly polarized beam

2020 ◽  
Vol 44 (5) ◽  
pp. 699-706
Author(s):  
A.G. Nalimov ◽  
E.S. Kozlova
Keyword(s):  
Angular Momentum ◽  
Energy Flow ◽  
Longitudinal Component ◽  
Angular Momentum Vector ◽  
Spin Angular Momentum ◽  
Momentum Vector ◽  
Circularly Polarized ◽  
Left Hand ◽  
Left Handed ◽  
Polarized Beam

It has been shown theoretically and numerically that in the sharp focus of a circularly polarized optical vortex, the longitudinal component of the spin angular momentum vector is inverted. Moreover, if the input light to the optical system is left-hand circularly polarized, it has been shown to be right-hand polarized in the focus near the optical axis. Since this effect occurs near the focus where a backward energy flow takes place, such an inversion of the spin angular momentum can be used to detect the backward energy flow.

scholarly journals Towards New Chiroptical Transitions Based on Thought Experiments and Hypothesis

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1103
Author(s):  
Takashiro Akitsu ◽  
Sanyobi Kim ◽  
Daisuke Nakane
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Azo Dyes ◽  
Uv Light ◽  
Polarized Light ◽  
Dipole Transition ◽  
Spin Angular Momentum ◽  
Cd Spectra ◽  
Circularly Polarized Light ◽  
Circularly Polarized

We studied supramolecular chirality induced by circularly polarized light. Photoresponsive azopolymers form a helical intermolecular network. Furthermore, studies on photochemical materials using optical vortex light will also attract attention in the future. In contrast to circularly polarized light carrying spin angular momentum, an optical vortex with a spiral wave front and carrying orbital angular momentum may impart torque upon irradiated materials. In this review, we summarize a few examples, and then theoretically and computationally deduce the differences in spin angular momentum and orbital angular momentum depending on molecular orientation not on, but in, polymer films. UV-vis absorption and circular dichroism (CD) spectra are consequences of electric dipole transition and magnetic dipole transition, respectively. However, the basic effect of vortex light is postulated to originate from quadrupole transition. Therefore, we explored the simulated CD spectra of azo dyes with the aid of conventional density functional theory (DFT) calculations and preliminary theoretical discussions of the transition of CD. Either linearly or circularly polarized UV light causes the trans–cis photoisomerization of azo dyes, leading to anisotropic and/or helically organized methyl orange, respectively, which may be detectable by CD spectroscopy after some technical treatments. Our preliminary theoretical results may be useful for future experiments on the irradiation of UV light under vortex.

scholarly journals Mechanical Perspective on the Rotational Doppler Shift of a Single Photon

2020 ◽  
pp. 62-67
Author(s):  
Roberto Lozano
Keyword(s):  
Angular Momentum ◽  
Doppler Shift ◽  
Single Photon ◽  
Mechanical Energy ◽  
Rotational Velocity ◽  
Spin Angular Momentum ◽  
Theoretical Possibility ◽  
Circularly Polarized ◽  
Flat Spacetime ◽  
Mathematical Relation

A theoretical model that relates the rotational Doppler shift of a photon and the rotational velocity of the lenses traversed by the beam of light, is presented. The mathematical relation, which is resolved in the context of a four-dimensional Minkowski flat spacetime and Cartesian coordinates, relates the rotational Doppler effect of a circularly polarized electromagnetic wave, caused by the transfer of spin angular momentum from a rotating object (lenses), with the coordinate acceleration of the rotating object, in the counter-propagating direction in which the photons move, and its angular velocity. From the analysis of the solved equation, it can be considered the generated coordinate acceleration and the theoretical possibility that it was obtained from the mechanical energy of a rotating object traversed by a beam of light, which, in turn, would generate a coordinate acceleration difference in the parallel and counter-propagating direction in which the photons move.

Introduction of spin torques

2017 ◽  
Author(s):  
T. Kimura
Keyword(s):  
Angular Momentum ◽  
Giant Magnetoresistance ◽  
Spontaneous Magnetization ◽  
Magnetic Domain ◽  
Magnetic Multilayers ◽  
Transfer Effect ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Angular Momentum ◽  
Spin Torques

This chapter discusses the spin-transfer effect, which is described as the transfer of the spin angular momentum between the conduction electrons and the magnetization of the ferromagnet that occurs due to the conservation of the spin angular momentum. L. Berger, who introduced the concept in 1984, considered the exchange interaction between the conduction electron and the localized magnetic moment, and predicted that a magnetic domain wall can be moved by flowing the spin current. The spin-transfer effect was brought into the limelight by the progress in microfabrication techniques and the discovery of the giant magnetoresistance effect in magnetic multilayers. Berger, at the same time, separately studied the spin-transfer torque in a system similar to Slonczewski’s magnetic multilayered system and predicted spontaneous magnetization precession.

scholarly journals Statistical evaporation of rotating clusters. II. Angular momentum distribution

2003 ◽  
Vol 119 (18) ◽  
pp. 9469-9475 ◽  
Author(s):  
P. Parneix ◽  
F. Calvo
Keyword(s):  
Angular Momentum ◽  
Momentum Distribution

A model for calculating the angular momentum distribution of fission fragments

1969 ◽  
Vol 136 (2) ◽  
pp. 465-480 ◽  
Author(s):  
J.O. Rasmussen ◽  
W. Nörenberg ◽  
H.J. Mang
Keyword(s):  
Angular Momentum ◽  
Momentum Distribution ◽  
Fission Fragments

Accretion of Mass and Spin Angular Momentum by a Planet on an Eccentric Orbit

Icarus ◽  
1997 ◽  
Vol 127 (1) ◽  
pp. 65-92 ◽  
Author(s):  
Jack J. Lissauer ◽  
Alice F. Berman ◽  
Yuval Greenzweig ◽  
David M. Kary
Keyword(s):  
Angular Momentum ◽  
Spin Angular Momentum ◽  
Eccentric Orbit
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