3,477 reputation
831
bio website migdal.wikidot.com/en
location Castelldefels, Spain
age 28
visits member for 3 years, 5 months
seen Apr 15 at 16:11

A PhD student in Theoretical Quantum Optics at ICFO. Alumnus of Physics and Mathematics at the University of Warsaw. Interested in quantum optics & quantum information, applied optics and mathematical modeling in psychology. Dedicated to education of gifted schoolchildren (as both tutor and organizer). In free time enjoys photography, hiking and psychology (esp. cognitive science).


Mar
13
comment Which symmetric pure qudit states can be reached within local operations?
If you have any critical remarks, I would be grateful (email or scirate.com/arxiv/1403.3069).
Mar
13
comment Function for curved line in log-log-plot
Why log-log plot? Did you try linear scale for temp?
Mar
13
accepted Schwinger representation of operators for n-particle 2-mode symmetric states
Mar
13
answered Schwinger representation of operators for n-particle 2-mode symmetric states
Mar
13
comment Which symmetric pure qudit states can be reached within local operations?
Take a look at: P. Migdał, J. Rodríguez-Laguna, M. Oszmaniec, M. Lewenstein, Which multiphoton states are related via linear optics?, arXiv:1403.3069 (where I acknowledge you and this thread). Thanks once again!
Jan
9
awarded  Popular Question
Nov
9
awarded  Yearling
Nov
7
comment What is the physical interpretation of the density matrix in a double continuous basis $|\alpha\rangle$, $|\beta\rangle$?
One interpretation is that they are complex probabilities, see iopscience.iop.org/1367-2630/14/4/043031/pdf/….
Sep
27
comment Introduction to relativity books for an engineer
@LarryHarson I am trying to push the author into translating it into English.
Sep
3
awarded  Good Question
Aug
13
awarded  Popular Question
Jul
18
reviewed Reject suggested edit on Negative probabilities in quantum physics
Jun
20
comment An entropy of the Wigner function
I was thinking about setting up a collaborative blog (for such things), but now I am short of time. So how about writing stuff there: writelatex.com/238489dmsdpc ? Or, alternatively, we can set up an open GitHub repository on that...
Jun
18
comment An entropy of the Wigner function
When it comes to breaking, i use $S_W-S_q-S_p$ for this formula with $S_w=-\int W\ln|W|$. Results for he subsequent Fock states are: [0., -0.0103, 0.2693,0.2950,0.4470,0.4770] where for the ground state $S_W=2.1447$. So this -0.01 is a relatively small breaking.
Jun
18
comment An entropy of the Wigner function
(Maybe let's go to other place, as SE is deliberately not well-suited for discussions. Any ideas? just in case: pmigdal@gmail.com) OK, two more things: 1) why $W(q,p)\leq\langle q|\rho|q\rangle>$? 2)still I am not sure why $2\pi W(q,p)^2 \leq \langle q|\rho|q\rangle \langle p|\rho|p\rangle$; for squeezed pure states states (a gaussian with main axes e.g. q+p and q-p) both sites integrate to 1 but the inequality is sharp.
Jun
18
comment An entropy of the Wigner function
It was a bit open-ended question. My main goal was to find a more general uncertainty principle than the entropic uncertainly relation. Wigner function looks like a good candidate, as it is a "quantum analogue" of the phase-space distribution.
Jun
13
comment An entropy of the Wigner function
I meant this line with $\text{Tr}(\rho)^2=1$.
Jun
12
comment An entropy of the Wigner function
When it comes to $2 \pi \hbar W (q,p)^2 \le \langle q \lvert \hat \rho \rvert q \rangle \langle p \lvert \hat \rho \rvert p \rangle$ - unfortunately, it cannot work. For pure stats (and not only being a product in $q$ and $p$, i.e. when the inequality is saturated everywhere) it is 1.
Jun
12
comment An entropy of the Wigner function
For n=1 it is not a Gaussian function. When it comes to "how much" I would need to dig in my notes (I will try to do that this week).
Jun
12
comment An entropy of the Wigner function
Thanks. Incidentally, I've tied the approach with $-\int W(q,p) \ln|W(q,p)| dq dp$. Then $S_w\leq S_q + S_p$ looked very promising... until I've found that for the first excited state (i.e Fock state n=1) it is broken by a tiny amount (and in fact it was the only state for which it does not hold).