ENANTIOMERIC EXCESSES INDUCED IN AMINO ACIDS BY ULTRAVIOLET CIRCULARLY POLARIZED LIGHT IRRADIATION OF EXTRATERRESTRIAL ICE ANALOGS: A POSSIBLE SOURCE OF ASYMMETRY FOR PREBIOTIC CHEMISTRY

2014 ◽  
Vol 788 (1) ◽  
pp. 79 ◽  
Author(s):  
Paola Modica ◽  
Cornelia Meinert ◽  
Pierre de Marcellus ◽  
Laurent Nahon ◽  
Uwe J. Meierhenrich ◽  
...  
2021 ◽  
Author(s):  
Zhaoming Zhang ◽  
Takunori Harada ◽  
Adriana Pietropaolo ◽  
Yuting Wang ◽  
Yue Wang ◽  
...  

Preferred-handed propeller conformation was induced by circularly polarized light irradiation to three amorphous molecules with trigonal symmetry, and the molecules with induced chirality efficiently exhibited blue circularly polarized luminescence. In...


Author(s):  
Peerasak Chantngarm ◽  
Kou Yamada

We present an analytical study of effects that off-resonant circularly polarized light irradiation has on spin-valley currents in dual ferromagnetic-gate silicene-based junctions. Two identical electric fields are applied to both ferromagnetic (FM) gates. Two types of exchange field configurations, parallel (P) and anti-parallel (AP), are applied along with chemical potential to the FM gates in this investigation. The results show that application of circularly polarized light has an impact on polarized spin and valley current characteristics, particularly at the off-resonant frequency region. It also enhances the amplitude of tunnelling magnetoresistance (TMR) significantly. In addition, we found that exchange field configuration has an effect on both spin polarization and valley polarization. Our study reveals that light intensity plays the main role on the light irradiation effects, where the band structure and change electronic properties of the materials are modified by photon dressing to create a new phase of electronic structure. The change of band structure in each region affects the transmission coefficients and transmission probability amplitude of electrons, which in turn affects the conductance of each spin-valley current component. Our study suggests the potential of this scheme in applications, such as spin-valleytronic photo-sensing devices under polarized-photo irradiation.


2001 ◽  
Vol 3 (6) ◽  
pp. 921-924 ◽  
Author(s):  
Hideo Nishino ◽  
Atsuko Kosaka ◽  
Guy A. Hembury ◽  
Hiroshi Shitomi ◽  
Hideo Onuki ◽  
...  

1999 ◽  
Vol 18 (3) ◽  
pp. 143-154 ◽  
Author(s):  
Yuichi Shimizu

It has been found that the irradiation with highly intense circularly polarized light (CPL) from an XeF (351 nm) laser can induce the enantiodifferentiation of racemic methionine with reasonable enantiocontrol by switching the sense of the CPL. Also, a similar result was obtained for threonine and it was newly revealed that the enantioenrichment is largely affected by the chemical structure, especially the functional groups, of α-amino acids, to cause photodecomposition such as decarboxylation and deamination. Furthermore, it was shown for the first time that the irradiation of a proline (Pro)-valine (Val) mixture with the CPL induces their enantioselective decomposition simultaneously, suggesting the occurrence of intermolecular interaction between Pro and Val.


Author(s):  
Marcos F. Maestre

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.


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