Hey guys, I decided to look up what this (TMTSF)_2ClO_4 thing is. Turns out it's an organic semiconductor. There is a picture here:
http://hoffman.physics.harvard.edu/materials/Cuprates.php
This was the first material to be superconducting at ambient pressure. Cool. These guys have some STM images of the material, which are quite pretty also:
http://avspublications.org/jvstb/resource/1/jvtbd9/v9/i2/p1013_s1
some of the other papers look like they have some pretty crazy maths:
http://prb.aps.org/pdf/PRB/v55/i3/p1299_1
but it looks like a really interesting material. Thoughts?
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Nice pictures!
ReplyDeleteReading the maths, it doesn't look too crazy.
Looking at the Lebed article (last link), the dispersion relation...it's understandable!
I suppose it looks a little more complicated because it's in 3D and we've mainly been working in 2D -> 1D.
Its Fermi surface (Fig. 1) is open much like what we were playing with in our assignment.
difference however, there is discontinuity in the surface,i.e. the arms aren't attached.
Looks a little odd.
yeah, I guess you're right about the maths. It really shows how nice 2D looks...
ReplyDeleteIf you look at the crystal structures of (TMTSF)_2ClO_4 and other superconductors listed in your first link, they do seem suspiciously similar-like layered cakes. It probably has something to do with electrons moving easily in the 2D plane. I recall they have similar phase diagrams as well.
ReplyDeleteActually looking at your first link again,
ReplyDeletethe crystal structures.
They just show a unit cell - implying that there is periodic repetition of the unit cells.
Seems intuitive now.
Looking at your second link,
they mention looking at the desnity of states near the Fermi level to find the elcetronic properties of the material. (So exciting stuff must happen at the Fermi level!)
Density of states refers to the distribution of electron states over a range of energies.
If we consider the Fermi-Dirac distribution, the interesting behaviour would be at the energy where the states vhange from filled to empty.
The same happens here where they have looked around the Fermi enrgy and found a gap in the density of states.
Sidenote: the Wikipedia entry for density of states is quite readable.