Abhinav
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 Dec 18 comment The minimal knowledge required for theoretical research in Quantum computing & AMO physics I'd like to point out that the course website mentioned also has an updated version of the notes, with many typos fixed- the direct link is here. Oct 4 awarded Popular Question Apr 28 revised What does it mean for a Hamiltonian or system to be gapped or gapless? Modified the LaTeX string to better represent the thermodynamic limit Apr 28 suggested approved edit on What does it mean for a Hamiltonian or system to be gapped or gapless? Apr 23 comment Entanglement of coherent states Interesting! At first glance, even I thought that this would be a Gaussian state. A useful rule of thumb would be to start off in a coherent state and imagine trying to create the state with just displacement and squeezing operators acting on it. @Ilya, it is true that they are entangled if a subsystem is mixed, but the connection between local purity and amount of entanglement between two subsystems is not so obvious (it's not, in general, a monotone), see here: maths.nottingham.ac.uk/personal/ga/papers/2251.pdf Feb 20 comment Accurate quantum state estimation via “Keeping the experimentalist honest” +1 for "V-Wade". :D Feb 20 comment The Simon's Algorithm, confusing equation @Makaveli, if the answer satisfies you, please consider accepting it. Thanks! :) Feb 20 comment The Simon's Algorithm, confusing equation Out of curiosity, what book are you using? Feb 20 answered The Simon's Algorithm, confusing equation Nov 27 comment Physical meaning of the angular momentum Good answer, but it needs jens_bo's answer in order to completely give the OP an idea of why "we need to multiply linear momentum by position". Sep 30 awarded Explainer Sep 28 awarded Yearling Sep 10 comment The triangle inequality in CHSH derivation, where is the triangle? In equation 6 of the Wikipedia link in the question, we have something that reads like $X - Y = a - b$, which upon taking the modulus becomes $|X - Y| \leq |a| + |b|$. Here the modulus is simply the absolute value of the real numbers X, Y, a and b. So there is no length in "metres", because there is no length scale associated with this problem. I am sorry if my previous comment confused you, the vectorial notation is not really necessary since you are simply dealing with numbers on the real line here. Sep 10 comment The triangle inequality in CHSH derivation, where is the triangle? The triangle inequality is a special case of the Cauchy-Schwarz inequality, which is the one applicable here since you are taking norms of the expectation value. The "triangle" formed is the one with the sides $\bar{X}$, $\bar{Y}$, and $\bar{X}+ \bar{Y}$. May 10 comment Why didn't we replace our SI units with a better system? @GlenTheUdderboat it seems like you have missed three important negative signs in the exponent for the values of $h$, $e,$ and $k$. Apr 29 comment Weak measurement and Hardy's paradox Is the 3rd condition supposed to be B' = -1? The third paragraph that follows the conditions and the wave function seem to indicate this. Apr 4 awarded Excavator Apr 4 revised Aharonov-Bohm Effect and Integer Quantum Hall Effect The earlier link was broken, updated it now. Apr 4 suggested approved edit on Aharonov-Bohm Effect and Integer Quantum Hall Effect Feb 21 awarded Citizen Patrol