Recent content by Cthugha

Just to add to all the correct comments that were made already: The wording above is dangerous because it mixes two different pictures. In chemistry, often real-valued orbitals are preferred, while in physics often complex-valued ones are used. When you explicitly talk about m=1, this implies...

Your question confuses me because both show essentially the same data. Baluncore already explained it well, but just to add a simplified summary: You use the self-heterodyning to get the noise you are interested in to a frequency range where little other noise sources are. So (oversimplifying -...

Yes, but you of course still expect the typical properties a density operator needs to have, for example that they are trace class. Of course one must be careful here from the mathematical and formal point of view as some things are different for infinite-dimensional stuff. For example, there...

Why not? This is typically the case for bosonic systems. Consider, e.g., a standard quantum mechanical harmonic oscillator in the Fock (occupation number) basis. In principle, the Hilbert space is infinite-dimensional. In practice, of course there is only a finite amount of energy available and...

Also, even if you had a detector with equivalent detection efficiency for photons arriving from both sides, such a detector would be an experimental nightmare. The quantity you are interested in is the path length difference of the two photons as a fraction of their wavelength. Now the detector...

You seem to be missing one very important point: This is a review article (not a regular one) and they never did these experiments. As pointed out by DrChinese these are just "gedankenexperiments", which were never actually performed at that time. They just present the results expected from...

I do not exactly get what you consider weird about that. Maybe you can clarify. Indeed in solar cells you create an exciton (bound electron-hole pair) or free electrons and holes. If you leave them unattented and just wait, the electron will reduce its energy by scattering and move to the...

Are you sure that this should be an advanced level thread and you are on grad student level? In a semiconductor, the electron is not removed from an atom by optical excitation. It goes from the valence to the conduction band. In neither of those bands the electron can be assigned to a single...

That is spatial coherence or the transverse coherence length. It tells you how point-like the light source is or what the maximal separation of slits may be to observe interference in a double slit experiment. For interference filters, the longitudinal coherence length (coherence time times the...

There are some openly available tools (called MonacoQC, Matlab-based) for simulating quantum cascade structures on the Github of the computational photonics group of TU Munich: https://github.com/orgs/cph-tum/repositories I have no idea how versatile or easy to use they are, but maybe this is...

The upper image looks like what you would see if the two beams overlap at the position of the camera, but are not perfectly parallel. How do you check the alignment of the beams? For adjusting an interferometer, one may have a look at the two beams in real space and try to overlap them and then...

Is there any specific reason why you choose quantum dots for this? At least self-organized QDs are usually lens-shaped and therefore inherently asymmetric. The symmetry properties are much better, e.g., for single ions in a Paul trap. This is not exactly the geometry you mention, but I think...

That sounds like you are working on the KATRIN measurement for precisely measuring Neutrino masses via tritium beta decay. I am a semiconductor (Rydberg) physics guy, but one person from our astroparticle physics department who has ties to people working at KATRIN once asked me about Rydberg...

Unfortunately, there are several different meanings of "coherent light" and one needs to consider the statement by Hanbury Brown in the context of his famous experiment. There is second-order coherence, which is about correlations in photon detections. Here, coherent light will indeed show no...

When discussing whether something is a quantum Cheshire cat, it might be helpful to have a look at Aharonov's original paper introducing the term and the experimental setup: https://iopscience.iop.org/article/10.1088/1367-2630/15/11/113015 This is New J. Phys. 15 113015 (2013). It is an open...