Recent content by DeathbyGreen

Hi, I'm trying to find a database in which I could enter a chemical formula and then locate a table of physical properties of that compound (or references). For example, whether the material exhibits magnetism, superconductivity, it's crystal structure, curie temperatures, conductivity, or...

Here is a link list from MIT that includes programs in Europe: http://web.mit.edu/jbelcher/www/hp.html Not all of the links work, so you'll have to individually search ones that are broken. Good luck!

You can do a Physics PhD which specializes in physics education. Rather than doing research for your dissertation you would be writing about improving educational techniques or something of the sort. Here is an example: https://web.phys.ksu.edu/info_us/degrees.html I'm not plugging that program...

So during my PhD I've done one analytic based theory paper with one advisor and will now do an experiment paper with another advisor. I'm curious as to how this will look applying for postdocs. Would this allow me to apply for either theory or experiment? Or would it just make me look not...

Yes, the system without the potential would have an inversion symmetry, with the potential term this symmetry is broken. It makes sense seeing the paper; before I was saying that breaking inversion symmetry in certain crystal structures can create electric fields. Here all they seem to mean is...

How did you get from \psi(x) = \int_{\infty}^{\infty}\phi(p)e^{ipx}dp to \int_{\infty}^{\infty}\frac{\phi(p)e^{ipx}}{p}dp? I'm not sure just dividing by \hat{p} is correct; taking the inverse of an operator can change the domain that the operator is applicable in. Inverse operators can be...

Inversion symmetry is simply flipping a system and seeing that it looks the same after flipping. So if you have something, then you turn it upside down, and it looks the same, you would say that object has inversion symmetry. For example, a layered system ABC -> CBA, or z \rightarrow -z ...

Maybe you could post the paper? It would make it easier to see the context. 1) Yes, a many body Hamiltonian would look different (would have summations involved) 2) The potential looks to have a form similar to a Heaviside theta function; it is on at the interface at z=0 and to the right of it...

Maybe I'll offer some input as well. Both Dishsoap and Crysphys made some good points. I sympathize with you a little bit because I've bounced around as well during my education. Started engineering, then MS experimental solid state, now a PhD in theoretical solid state. I was in almost the same...

The integral occurs in a conductivity calculation I'm working through, it has a imaginary convergence factor in the denominator which I didn't write. So you think I could evaluate this as a standard contour and not need the fancy QFT loop integral forms?

Hi, I'm trying to calculate an integral which looks unfortunately divergent. The structure is similar to a loop integral but the appendix in the Peskin textbook didn't have a useable form. The integral form is (I did a u substitution to make it easier to look at) \int_x^{\infty}du...

Disregard I got it; I was using a wrong Minkowski metric relation

I'm trying to work through a scattering calculation in the Peskin QFT textbook in chapter 5, specifically getting equation 5.10. They take two bracketed terms 4[p'^{\mu}p^{\nu}+p'^{\nu}p^{\mu}-g^{\mu\nu}(p \cdot p'+m_e^2)] and 4[k_{\mu}k'_{\nu}+k_{\nu}k'_{\mu}-g_{\mu\nu}(k \cdot...

I'm trying to relate some different frequencies together in an experiment. Say I have 3 different frequencies, \omega_1,\omega_2, \omega_3. Omega 3 is the large envelope, and the other two must fit inside of it, and so they are integer multiples of each other. Is there some way to express...

So a couple of things: 1) I'm not sure about your problem statement. You say that k is the number of particles in a given state. This should be n_k. In occupation number representation the number operator n_k returns the number of particles in the k^{th} momentum state. 2) Are you using...