Recent content by zje

I might be a little out of my league, but I'm trying to work through the DLCZ protocol for quantum communication (http://arxiv.org/abs/quant-ph/0105105). I've read the paper and gone through the introductory parts of this thesis: http://thesis.library.caltech.edu/2059/, but I'm still unclear on...

Conservation of energy - remember that the energy of a photon is inversely proportional to its wavelength. The incoming photon transfers its energy to the electron and the energy (photon) that is released out must be the same, therefore the wavelength is the same. This may be oversimplified, but...

I have a quick question. I've been trying to search for an answer, but I'm probably looking in the wrong places. Is it valid to have negative off-diagonal elements in a density matrix? Thanks!

Are you coupling with a poisson solver? If so, how does that look? How are you handling Vg and Bias in the MOSFETs? Sorry, I'm not too much of an expert in NEGF...

Homework Statement \omega^2=(2/M)\sum_{n>0}\frac{A\sin(nk_0a)}{na}(1-\cos(nKa)) A, a, and k_0 are constants, n is an integer. I need to find \omega^2 and \frac{\partial\omega^2}{\partial K}, but I have no idea where to start.Homework Equations Not sure, the stuff above.The Attempt at a...

I tried expanding the exponent term and couldn't find a way to integrate by parts that made it simpler. Looking at it again, would the simple substitution be u=(x - a*cos[wt]), du=dx? Thanks for your reply!

Homework Statement A particle of mass m that is confined to a harmonic oscillator potential V(x) = \frac{1}{2} m \omega^2 x^2 is described by a wave packet having the probability density, |\Psi (x,t) |^2 = \left(\frac{m\omega}{\pi\hbar} \right )^{1/2}\textrm{exp}\left[-\frac{mw}{\hbar}(x -...

I'm a grad student in ECE and it's been about 5 years since I took a complex analysis course. Unfortunately, I didn't use any of it after the class, so I'm more than a little rusty. Time to whip out some old textbooks and start digging. Thanks!

Homework Statement I'm working on converting a single-dimension wavefunction to its momentum representation. Here is the integral I am stuck with (I've pulled out some constants): \int\limits_{-\infty}^{\infty}\frac{e^{\frac{-ipx}{\hbar}}}{x^2+a^2}\textrm{d}x Homework Equations...

Thanks all for your help, I think I got it!

Just realized that it shouldn't end at \textrm{tan}^2\theta but \frac{1}{a} \int \frac{\textrm{tan}^2\theta}{\textrm{sec}^2\theta}\textrm{d}\theta = \frac{1}{a} \int \textrm{sin}^2 \theta \textrm{d}\theta I'm still unsure of what exactly to do with the limits...

Homework Statement It's been a couple of years since I've done real math, so I'm kinda stuck on this one. This is actually part of a physics problem, not a math problem - but I'm stuck on the calculus part. I'm trying to solve this guy: \int \limits_{-\infty}^{\infty}...

Very true, some of the best Programmers/SysAdmins I've ever known had degrees in physics.

Not to throw everything off, but do you want to do something physicsy with CS? I've known tons of people who've made the (post-undergrad / career) switch from physics to CS. Not so much the other way around - I believe it would be far more difficult. Just some food for thought

It seems that I can get E_f - E_i rather easily and if my assumption for E_c - E_i is correct, then E_c - E_f = (E_c - E_i) - (E_f - E_i), which is what I think I'm looking for. However, I'm somewhat hesitant to believe it's that simple. Maybe the trick is to get more sleep :-)