What is mysterious about the so called quantum eraser? A typical double slit experiment produces an interference pattern on the screen. In a double slit quantum eraser experiment there are additional polarizers or splitters and the interference comes and goes depending on the setup. On the ima...

Can sombody explain me what a quantum potential Cause I read an article on Ford that say that the universe could eternal existing in some sort of quantum potential before collapsing into the bid bang

superposition is supposed to be part of "the other worlds", right? once we measure it then its our world and the other positions aren't relevant? what if you do an experiment, let's say double slit, where in all other universes you block the electron from entering the right slit. this means it s...

Consider a finite-dimensional non-relativistic QM system with hamiltonian $H$. Let $K$ denote the complex conjugation operator. What does $K H K$ simplify to, if the system is: (a) spin-zero; (b) spin-half? I'm thinking it's maybe $H^*$ or $-H^*$, where asterisk denotes complex conjugation (not h...

I have a homework problem that asks us to determine $[f(\hat{x}),\hat{p}]$ only by use of $[\hat{x}^n,\hat{p}] = nih\hat{x}^{n-1}$ as well as assuming $f(\hat{x})$ can be expanded into a maclaurin series. h should be h-bar, I couldn't figure out how to do strikethrough text. My solution has me ar...

I don't know if the law of addition is broken in quantum physics. For example an electron is 100% wave and 100% particle, but one electron. is that 1+1=1. And do you get the same thing with Schrödinger's cat, which is both dead and alive I'm not a physicist so this might sound like a stupid/easy...

If we have an observable $A$, and a unitary operator $\hat U$, one can easily show that both $\hat A$ and $\hat U \hat A \hat U^{\dagger}$ have the same spectrum - in fact, they are called unitarily equivalent. For example, in Stern-Gerlach experiment, one can easily show that $S_x$ and $S_z$ op...

I have trouble understanding how the operators that change the initial state, change when adding extra splitters. As an example, I will use an idealized Mach-Zehnder interferometer where the splitters have no thickness. I am using the picture from Mach-Zehnder Interferometer: two output interf...

I know that for time independent Hamiltonians we can make the statement $$U = e^{-iHt}\tag{1}$$ where $H$ is a time-independent Hamiltonian and U the unitary, also known as time evolution operator. Now when studying I've met a unitary which corresponds to a two-level rotation defined as $$...

I found that : $[N,H] = 0$ , With $N=|e><e|+a^+a$ is the number of excitations and $H$ is the Hamiltonian of Jaynes-Cummings. and i want to describe the dynamics of the system(atom of two levels and one mode of quantized field). so why one can reduce the whole Hilbert space to the subspace span...

Disclaimer: I've asked a very similar question before (which I can provide if desired, but it shouldn't contain anything that is not stated here), but it was downvoted and eventually deleted for reasons unknown to me (hence, if you're going to downvote this question, please tell me why!). However...

The math suggests that there are 11 or more "dimensions", most of which we know very little about. What if entangled particles are linked in one of those "other dimensions" and when we separate them in our view of space and time they remain linked in their other dimension. That way, there is no...

Does using Roman Baudrimont's calculations for the dynamic viscosity of space-time and applying the fluid dynamics of pressure mediation and vortex motion explain gravity better then current standard relativity?

Show that $$ \phi_p(r) =(\frac{1}{2\pi\hbar})^{3/2}e^{ip\cdot r/\hbar}$$ is an eigenstate of p, where p and r are 3D vectors. I'm unclear on what the final equation I'm trying to get to should look like. I thought that the final result would be showing that $\phi_p$ is equal to $ap$, with ...