A New Spin on Photoemission Spectroscopy Page: 32 of 259
This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
ratio, or 'g-factor' is ;2), giving the correct expression for the total magnetic moment of
an electron as
y = pB (Jl h) (L + 2S) . (1.15)
As the spin of an electron is either h/2, the intrinsic magnetic moment of an electron is
S= B2S = B. (1.16)
With electron spin in mind, we can now understand the SGE results. The filled subshells
of the Ag atoms net zero orbital angular momentum. With each orbital filled with both
a spin-up and -down electron, these shells net zero spin momentum as well. The final
unpaired 5s electron has l = 0 and so the only contribution of angular momentum comes
from the one electron spin. The two values of the spin component along the z-axis is then
the source of the two branches of the split beam. But what about the magnitude of the
splitting? With L = 0 and S = 1/2, equation 1.15 gives the total magnetic moment of
the Ag atoms to be PB, in perfect agreement with Stern and Gerlach's results showing a
splitting corresponding to a difference in magnetic moment of 2pB. Although the results of
the SGE were widely known, it is interesting to note that the discoverers of the spin of the
electron made no mention of the SGE in relation to their discovery at the time.
It should also be noted that spin should not be interpreted as a classically rotating
sphere. As Lorentz argued to Uhlenbeck, this was not possible. Spin is a purely quan-
tum mechanical quality, following the quantum rules of angular momentum with quantum
number s = 1/2 with a magnetic moment of pB. Both the spin and magnetic moment of
the electron (with gs~2) are automatically contained in the relativistic Dirac description of
electrons, but have no direct classical explanations.
1.2.3 Spin-orbit coupling
One of the many effects of the electron having an intrinsic spin angular momentum is
the coupling between the spin and the electron's own orbital angular momentum. This is
referred to as spin-orbit coupling and can be an important interaction in determining solid
Here’s what’s next.
This document can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Thesis Or Dissertation.
Jozwiak, Chris. A New Spin on Photoemission Spectroscopy, thesis or dissertation, December 1, 2008; United States. (https://digital.library.unt.edu/ark:/67531/metadc1014237/m1/32/: accessed April 22, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.