Attenuation of longitudinally polarized electron beams by chiral molecules

Abstract

The attenuation of a longitudinally polarized electron beam in an optically active medium is discussed. A general theory is developed and numerical results are presented for a chiral model molecule.

Evaluation of spin-flip scattering in chirality-induced spin selectivity using the Riccati equation

“…which is consistent with previous models [25,26,33]. Without spin-dependent absorption ∆α = 0, obviously no asymmetry will be observed, though spin-flip effects may be present.…”

“…The inverse of the parameters α 1 , α 2 , f 1 , and f 2 denotes the mean free path of the respective process. For this configuration we can set up coupled differential equations [25] dN…”

“…In the following we abbreviate spatial derivatives in the form dN i (x) dx = N ′ i (x), and for convenience we omit to write the x dependency explicitly, e.g., N i (x) = N i . In an extension of the model of Fandreyer et al [25] we retain the spin-flip contributions f 1 and f 2 . The differential equations (2a), (2b) can be rearranged to obtain a differential equation for the spin polarisation P which is independent from the number of electrons in both spin states N = N 1 +N 2 .…”

“…CISS is sensitive to the longitudinal component of the electron spin, so the parameters of interest are spin-dependent losses and spinflips between the spin-up and spin-down channel. A very intuitive way to describe the change of spin polarisation in the longitudinal direction by forward-scattering was found by Fandreyer et al [25]. A pair of differential equations describe the change of the expectation values for the number of spin-up, N 1 , and spin-down electrons, N 2 , as coupled rate equations.…”

Circular dichroism in valence photoelectron spectroscopy of free unoriented chiral molecules: Camphor and bromocamphor

“…This factor should depend on the degree of dissymmetry in the structure of the molecule. (4) As was predicted theoretically by Farago [22], and by Fandreyer et al [23], the spin-orbit (SO) interaction plays an important role in the formation of the electron dichroism (ED) in the electron scattering from chiral molecules. In corresponding experiments for the scattering of spin-polarized electrons from chiral molecules in the gas phase by Mayer and Kessler [24], Nolting et al [25], and Kessler [26], the scattering cross sections showed a spin-related dependence.…”