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Feb2313 08:38 AM
ZapperZ

1 
30,383 
I'm wondering whether or why quantum entanglement swapping or steering could or couldn't be used for superluminal...

Mar714 03:43 PM
UltrafastPED

1 
208 
I understand mathematically etc how light can doppler shift when looked at as a wave but can it be understood how...

Mar614 09:54 PM
The_Duck

2 
228 
we know that an electron rotates about its own axis.similarly does the electron too rotates about its own axis? and...

Mar614 02:18 PM
ZapperZ

2 
194 
The Wikipedia entry on uncertainty says, "Since the Robertson and Schrödinger relations are for general operators, the...

Mar614 11:44 AM
anorlunda

6 
206 
A laser's beam is split and then recombined, and the two path delays are adjusted so there is destructive interference...

Mar614 10:42 AM
Nugatory

8 
301 
I believe the title says it all.
What is the first and second quantization? What is the difference?
Thank you.

Mar614 09:13 AM
bhobba

3 
191 
In infinitely potential well problem ##V(x)## is zero inside the box and ##\infty## outside the box. Is it possible to...

Mar614 02:40 AM
vanhees71

35 
816 
Hi Guys,
Newbie question from a layperson so please don't beat me up! :D
I know that Heisenberg's Uncertainty...

Mar514 07:12 PM
FactChecker

13 
384 
Hi All,
In the Feynman, 'sum over paths' approach to quantum field theory, we compute amplitudes, generating...

Mar514 06:45 PM
bhobba

3 
367 
Hey,
I've been searching around for papers reporting on the creation of relatively large cat states, the largest I...

Mar514 09:31 AM
Gwinterz

2 
255 
Question and symbols:
Consider a stateε> that is in a quantum superposition of two particleinabox energy...

Mar514 08:44 AM
Simon Bridge

12 
462 
Just a thought...
Say that a stationary (relative to me) source of light emits a photon with the energy level (as...

Mar414 07:43 PM
samalkhaiat

7 
334 
If you ask me define Dirac delta function, i can easily define it and prove its properties using laplacian or complex...

Mar414 05:50 PM
bhobba

8 
341 
Hi,
I was reading about interference patterns. I was wondering if the classical interpretation of...

Mar414 11:32 AM
UltrafastPED

1 
209 
I have read in popular literature that it is hypothesized that one could shoot particles through a pair of plates...

Mar414 11:13 AM
phinds

1 
215 
If in quantum physics some state is represented by
## \psi(x)=\sum_{k}C_k\psi_k(x)##
##C_m=\int \psi(x)\psi_m(x)dx##...

Mar414 05:02 AM
naima

3 
266 
Hi! I'm a little confused about simple spectroscopy. In typical absorption experiments, we scan the laser frequency w...

Mar414 03:24 AM
rrbbss

7 
766 
I went through an undergraduate physics program and I've internalized the results of the Stern–Gerlach experiment to...

Mar314 10:58 PM
WannabeNewton

14 
646 
I have a doubt on the second quantization formalism. Suppose that we have two spin1/2 fermions which can have just...

Mar314 03:50 PM
Einj

2 
203 
Does Casimir plates prevent photon existence only perpendicular to them?
I mean, Casimir attraction arises from the...

Mar314 02:47 PM
Naty1

6 
349 
Hi guys.
Recentely I'm approaching Quantum Mechanics starting from the mathematical basics.
In order to understand...

Mar314 01:55 PM
chimay

3 
265 
In any textbooks I have seen, vacuum states are defined as:
a 0>= 0
What is the...

Mar314 11:39 AM
stevendaryl

13 
473 
Hi,
imagine setup with source of entangled photons (A and B). Photon A travels to double slit so that either wave or...

Mar314 11:16 AM
DevilsAvocado

5 
283 
I was reading Mandle QFT book, and it says: "If we require the vacuum states to be invariant under Lorentz...

Mar314 11:14 AM
Einj

7 
1,030 
I can't figure this one out given that the coordinate operator is continuous, it's hard to imagine "matrix elements"....

Mar314 10:53 AM
Heisenberg

3 
251 
We know how to find S_{x} and S_{y} if we used S_{+} and S_{}, and after finding S_{x} and S_{y}, we can prove that
...

Mar314 07:46 AM
ChrisVer

7 
275 
Why we don't have acceleration in quantum mechanics. For example why particle in infinite potential well can not...

Mar314 06:47 AM
ChrisVer

4 
243 
hi, please explain why do we need complex wavefunction in quantum mechanics?

Mar214 09:02 PM
ChrisVer

6 
383 
I have found that:
For l = 1:
\sum_{m=l}^l Y_l^m^2 = \frac{3}{4\pi}
For l = 2:
\sum_{m=l}^l Y_l^m^2...

Mar214 08:59 PM
Simon Bridge

4 
254 
if ψ(o)=(1 0)^{T} at time t=0.
According to some Hamiltonian, it was found that the corresponding eigenstates are...

Mar214 08:51 PM
ChrisVer

1 
182 
I'm reading the textbook "Silicon Nanoelectronics" and I've encountered an equation for the transmission probability,...

Mar214 02:29 PM
Achmed

6 
285 
In proving that for the norm to be preserved, U must be unitary. I ran across this:
Re(λ<øψ>)=Re(λ<UøUψ>)
if...

Mar214 02:07 PM
M. next

2 
225 
Hello,
I just recently learned about angular momentum operator. So far, I liked expressing my operators in this...

Mar214 12:12 PM
oomphgalore20

5 
439 
Hi, if ket is 2+3i , than its bra is 23i , my question is 2+3i is in Hilbert space than 23i can be represented in...

Mar214 06:43 AM
stevendaryl

3 
281 
I’ve been trying to understand how having indistinguishable particles in a system changes the nature of the state...

Mar114 11:41 PM
strangerep

7 
297 
Hello,
I am trying to recreate the double slit experiment using ordinary light, i.e. sunlight or light from a light...

Mar114 05:12 AM
craigi

4 
258 
I have questions about chapters 5 & 9 in Srednicki's book.
1.
Below eq. (5.18), he says "$<p\phi (0)0>$ is a...

Mar114 02:49 AM
JILIN

9 
393 
I have heard the argument that "decoherence" in quantum states causes the quantum collapse to occur, and that this...

Feb2814 01:10 PM
atyy

82 
1,766 
In deriving the Heisenberg uncertainty relation for 2 general Hermitian operators A and B , the uncertainty operators...

Feb2714 05:13 PM
dextercioby

3 
306 
Ok, well I'm not really sure if this is the right place to post this, but I have a simple question regarding nuclear...

Feb2714 04:49 PM
ZapperZ

12 
583 