Hello,
I have a question which has something to do with band structures etc:
A two dimensional solid has two electrons per unit cell. The crystal potential is weak and the solid behaves like a free electron metal.
Estimate the threshold for interband optical transitions in terms of the...
Hello, I think I am fundamentally confused with summation convention. For example, if I have
\epsilon_{ijk}x_j\delta_{jk}
Can I sift the levi civita and get
\epsilon_{ijj}x_j=0
or sift x and get
\epsilon_{ijk}x_k\not=0
Each gives a different answer. What mistake...