Surface Chemistry of Five-Membered Aromatic Ring Molecules Containing Two Different Heteroatoms on Si(111)-7 × 7

2007 ◽  
Vol 129 (15) ◽  
pp. 4815-4823 ◽  
Author(s):  
Feng Tao ◽  
Steven L. Bernasek
2010 ◽  
Vol 24 (21) ◽  
pp. 2201-2214 ◽  
Author(s):  
J. E. HIRSCH

I propose that the phase of an electron's wavefunction changes by π when the electron goes around a loop maintaining phase coherence. Equivalently, that the minimum orbital angular momentum of an electron in a ring is ℏ/2 rather than zero as generally assumed, hence, that the electron in a ring has azimuthal zero point motion. This proposal implies that a spin current exists in the ground state of aromatic ring molecules and suggests an explanation for the ubiquitousness of persistent currents observed in mesoscopic rings.


2016 ◽  
Vol 18 (3) ◽  
pp. 1570-1577 ◽  
Author(s):  
Masahiro Yamaki ◽  
Yoshiaki Teranishi ◽  
Hiroki Nakamura ◽  
Sheng Hsien Lin ◽  
Yuichi Fujimura

Stationary angular momentum, which is a fundamental quantity of high-symmetry aromatic ring molecules, can be created for low-symmetry ring molecules by applying theoretically designed stationary laser fields.


2016 ◽  
Vol 18 (38) ◽  
pp. 26786-26795 ◽  
Author(s):  
Hirobumi Mineo ◽  
Masahiro Yamaki ◽  
Gap-Sue Kim ◽  
Yoshiaki Teranishi ◽  
Sheng Hsien Lin ◽  
...  

A new laser-control scenario of unidirectional π-electron rotations in an aromatic ring molecule having no degenerate excited states is proposed.


2021 ◽  
Vol 9 ◽  
Author(s):  
Hirobumi Mineo ◽  
Ngoc-Loan Phan ◽  
Yuichi Fujimura

Herein we review a theoretical study of unidirectional π-electron rotation in aromatic ring molecules, which originates from two quasi-degenerate electronic excited states created coherently by a linearly polarized ultraviolet/visible laser with a properly designed photon polarization direction. Analytical expressions for coherent π-electron angular momentum, ring current and ring current-induced magnetic field are derived in the quantum chemical molecular orbital (MO) theory. The time evolution of the angular momentum and the ring current are expressed using the density matrix method under Markov approximation or by solving the time-dependent Schrödinger equation. In this review we present the results of the following quantum control scenarios after a fundamental theoretical description of coherent angular momentum, ring current and magnetic field: first, two-dimensional coherent π-electron dynamics in a non-planar (P)-2,2’-biphenol molecule; second, localization of the coherent π-electron ring current to a designated benzene ring in polycyclic aromatic hydrocarbons; third, unidirectional π-electron rotations in low-symmetry aromatic ring molecules based on the dynamic Stark shift of two relevant excited states that form a degenerate state using the non-resonant ultraviolet lasers. The magnetic fields induced by the coherent π-electron ring currents are also estimated, and the position dependence of the magnetic fluxes is demonstrated.


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