1,848 reputation
617
bio website math.berkeley.edu/~cgerig
location UC Berkeley
age 26
visits member for 3 years, 9 months
seen 7 hours ago

After doing my BS in engineering physics (with experimental research on gravity), I started my PhD in experimental atomic physics. But I quit to do math, and am now a 4th year student of Michael Hutchings.


7h
comment Rigourous Treatment of Antenna Theory/Physics
Staelin's Electromagnetic Waves, I've used this before, as did a physics course at Cornell, and it was rigorous. A book I haven't read, but downloaded because it looked like I need to read it, is Electromagnetic Waves and Antennas by Orfanidis... this might be more for what you what.
Aug
9
comment Ramsey pulse versus optical pumping: what's the difference?
This optical pumping, by definition, only hits the $|e_1\rangle$ state. If you want to "shine a laser" elsewhere, you are no longer describing the same phenomenon. I can pick up a soccer ball and start bouncing it, but I'm no longer playing soccer.
Aug
8
comment Ramsey pulse versus optical pumping: what's the difference?
The difference is that Ramsey-pulsing describes oscillations of the atom-photon interaction that occurs in a 2-level system, whereas optical pumping is a technique to get actual lasing from a 3-level system (since it is not classically possible with a 2-level system). The pumping field does not hit the $|e_2\rangle$ state, so there is no "oscillations" going on between it and the ground state.
Aug
3
comment Is an electron a superconductor?
I am arguing that it does exhibit such an effect, based on a vacuous description. There is no "inside" to the electron, hence no B-field "in the bulk". The B-field also doesn't attract the electron, if anything it directs the movement of the electron.
Aug
3
comment Is an electron a superconductor?
It comes down to semantics. If a superconductor is defined in terms of the Cooper pair quasiparticle, then the electron is not a superconductor. If a superconductor is defined by the two stated phenomena, then I think an electron is a superconductor -- an electron has no "bulk" to it, and its movement in a B-field is perpendicular to the direction of the field (i.e. not "attracted" to it). The point is that it's vacuously true and meaningless.
Aug
3
comment Is an electron a superconductor?
This is an irrelevant answer. You are only summarizing superconductivity, which anyone can read on Wikipedia. To me, you haven't addressed the question. For instance, the "critical temperature" might be infinite, i.e. the electron could always be superconducting. Since there is no "bulk" to the material here, it's vacuously true that there is no B-field "inside it" (which is what expulsion of the field means here). To me, what really makes an electron obviously not a superconductor, is that there is only one electron, whereas superconductor requires two electrons to form a Cooper pair.
Jun
29
awarded  Custodian
Jun
29
reviewed Reject What is the magnetic field inside hollow ball of magnets?
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnRennie You're not fixing the vacuum, an accelerated observer is the same as a stationary one in a gravitational field. The question refers to the object of light itself, which implicitly assumes you have a fixed observer. If you make an edit which clarifies this, I would gladly remove my downvote.
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnRennie Your last paragraph doesn't make any sense to me, and you have yet to explain it despite multiple people asking. I don't think you have an explanation, because light itself does not change in vacuum.
Jun
27
comment I know light's speed in vacuum is constant, but what about its velocity?
@JohnDuffield your answer is wrong because "vacuum" requires the absence of gravity.
Apr
12
comment Destroying currents in superconducting rings by vortex tunneling
Do you have a reference for details concerning your last paragraph?
Apr
9
revised Seiberg-Witten theory and Superconductivity
added 693 characters in body
Apr
9
answered Seiberg-Witten theory and Superconductivity
Apr
9
accepted Destroying currents in superconducting rings by vortex tunneling
Apr
8
revised Destroying currents in superconducting rings by vortex tunneling
deleted 34 characters in body; edited title
Apr
7
revised Destroying currents in superconducting rings by vortex tunneling
added 16 characters in body
Apr
7
comment Destroying currents in superconducting rings by vortex tunneling
Thanks for bringing up this related problem; I take it this has negligible effect on the role of SQUIDs. Can you elaborate on your last sentence? I would think the system size $L$ depends on both the ring's thickness $\delta$ and its length $l$. (I initially guessed that the rate of occurrence of vortex tunneling looked like $\text{exp}(-\frac{\delta}{\lambda}\frac{l}{\xi})$, but had no good basis for that guess.)
Apr
7
answered Destroying currents in superconducting rings by vortex tunneling
Apr
6
asked Destroying currents in superconducting rings by vortex tunneling