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Lecture 15: Continuity Equations
Solid State Physics
English - March 07, 2006 15:03Science Education Courses solid state physics condensed matter science fun materials Homepage Download Apple Podcasts Google Podcasts Overcast Castro Pocket Casts RSS feed
We derive the Einstein relations, which connect the conductivity with the diffusion coefficient. This is far more exciting than it sounds, because it's a consequence of the far-reaching fluctuation-dissipation theorem. Another instance of this theorem happens with Brownian motion, and the applet we used in class can be found at
http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/brownian/brownian.html
We also derive the continuity equations in a semiconductor, and see how fast they can screen a stray charge that may be produced by, say, thermal fluctuations. We highlight 2 applications of semiconductors: LED's and solar cells.
We discuss a bit the impending energy challenge, referring to a
talk by Nobel Laureate Richard Smalley. Sadly, he has
passed away.
Lecture Audio