## Known typos and errors in Lecture Notes 2012 January 9 Edition

[Note: This error list is not kept updated! Hopefully all errors are repaired in the book version.]
page 7. A sentence in the middle of the page ends with "we have". The table (table 2.1) at the top of the next page is meant to follow the "we have" (the table is placed in the wrong place).
page 9. Where it says "this result is easy to interpret" the language is incorrect. it should say that it is excited "on average up to the n_B^th excitation level" (meaning the ground state is counted as level 0 and the 1st excitation level is n=1).
page 32, in the last paragraph before section 4.3, in the expression for kappa, < v >^2 should not have the square (cf. first equation in Sec 3.2).
page 117. The 1d fourier transform (Eq. before 12.5). The prefactor should be 2 pi/|a|. Similarly in Eq. 12.5, the prefactor is (2 pi)^D /v with v the volume of the unit cell.
page 122. The first equation on this page is written so that x1,x2,x3 are measured in real lengths, not in units of a1,a2,a3. If you measure x1,x2,x3 in units of a1,a2,a3, then the equation should read 1/x1:1/x2:1/x3 = h:k:l
page 156. There is a |k> which should be |k'>
page 167. The energies in the footnotes are missing factors of hbar
page 178. Eq. 16.5. The hbar should be upstairs not downstairs.
page 179. Second equation. Mobility is incorrectly defined as |E|/|v|. It should be |v|/|E|.
page 184. It should say "the total density of electrons n in the conduction band" not "the total number. The error repeats on the following page for holes in the valence band (just below 16.6).
page 185. First equation on the page. It should be g_c rather than g_v.
page 185. Second equation on the page. The third and fourth expressions are both missing minus signs out front. The third expression is also missing a dy in the integral.
page 185. The equation after 16.6 the last expression on the right, in the denominator there is an extra minus sign in the exponential.
page 190. Below the figure. Twice in this pargraph it says "conduction band" where it should say "valence band"
page 202. The footnote is completely messed up. Symmetric and antisymmetric are confused.
page 210. proportional to radius, should be radius squared.
page 249. Superfluid is not a person (or a superhero).
## Known typos and errors in the homeworks

Problem 1.2. The data presented is not from KCl. It is actually from KI. So if you googled Debye Temperature for KCl you would not have found it in agreement with this data.
Problem 1.6d. The 2.08 and 2.6 have different units. The 2.08 is mJ/(mol-K) but 2.6 has units mJ/(mol-K^3)
Problem 3.2, the first part of this question is probably more precise if we remove the phrase "for the case where the axes of the lattice are all mutually orthogonal". (Miller indices and Crystal Planes are perfectly well defined even not in this case)
Problem 4.2d, the first sentence is more precise if worded as follows: "Consider a two-dimensional square primitive unit cell containing one divalent atom."
## Other errors

I mistakenly suggested in lecture that the idea of crystal momentum is not examinable. This is incorrect. Crystal momentum is examinable. (Connection to Noether's theorem is not).
The program ChainPlot had a bug in it for the alternating chain. Please download an updated version where this bug is fixed.
I stated in class that the interaction potential for a neutron with the nucleus is b*delta function of position, where b is the scattering length. This is dimensionally incorrect. The correct statement is that the interaction potential is (2 pi hbar^2)/m * b*delta function of positon, with m the mass of the neutron.