# Quantum Physics

- Mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics & Field Theory
 Meta Thread / Thread Starter Last Post Replies Views Views: 66,490 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Pinned: Quantum Physics Forum Rules Before posting anything, please review the Physics Forums Global Guidelines. If you are seeking help with a... Feb23-13 08:38 AM ZapperZ 1 34,018 I had posted this question here : http://physics.stackexchange.com/q/69003/540 I guess its appropriate to post... Jun30-13 10:13 AM The_Duck 1 421 Srednicki eqn. (2.23) and (2.24) states: We can make this a little fancier by defining the unitary spacetime... Jun30-13 07:25 AM omephy 2 621 Sorry for my abysmal level of ignorance, but I'm not understanding why quantum tunneling from nothing is considered a... Jun29-13 04:51 PM ZapperZ 2 420 Hello everyone, a number of books and web articles says that the minimum field required is ≈10^7V/cm for electrons... Jun29-13 08:30 AM ZapperZ 3 538 Hi :) In this lecture (http://www.youtube.com/watch?v=Igl8hE3Eac0), susskind talks about attractive the force... Jun29-13 05:09 AM FredericGos 3 608 Hello everybody, I am a first year student and I have a question about tunneling. If we have an electron which is... Jun28-13 11:59 PM Simon Bridge 9 953 Do the units of a wave function vary? i have heard that it just joules. What do you think? Jun28-13 02:40 PM dextercioby 11 1,205 In Zee's QFT book he writes an amplitude as: M(p)=\lambda_0+\Gamma(\Lambda,p,\lambda_0) He then states that you... Jun28-13 08:51 AM andrien 1 475 Say I have a particle in the rest frame with spin up in the z direction. If I boost the system in x direction, does... Jun28-13 07:13 AM DrDu 16 1,122 If we have twin photons moving in the opposite direction. For the first photon we can pass it through a polarizer... Jun27-13 09:47 AM TeCNoYoTTa 4 648 Let an electron is orbiting in a orbit with the principal quantum number n =1. According to wave mechanics its angular... Jun26-13 11:06 AM apr 3 684 In Zee's book at page 12 in both editions he finds that he can write the amplitude \langle q_f|e^{-iHT}... Jun26-13 07:29 AM andrien 5 863 Hi, I hope there is no issue with me posting this here but I'm stuck trying to get my head around DrChinese's page on... Jun26-13 06:45 AM Badvok 98 7,133 hi, i just need a quick clarification on pair production. from my limited understanding, a photon of... Jun26-13 04:20 AM mfb 1 478 Apologies if these questions have been answered before - I didn't have any luck with google. Something has bugged me... Jun25-13 07:10 PM cosmik debris 8 958 I just watched a video of James Gates and he discussed something he called the Gross Perrywall phase transition. It... Jun25-13 04:30 PM Skeezer 6 1,549 I'm not sure whether to post this here or not, but since the book is about quantum i figured it was as good a place as... Jun25-13 02:49 PM res3210 2 545 Hello, Can anyone please explain that how we can calculate the eigenvalues of a slab waveguide by using the... Jun25-13 08:26 AM engrriz 0 452 Bohmian Mechanics conflicts with so many observational facts: 1. Bohmian Mechanics severely violates Lorentz... Jun25-13 03:25 AM Demystifier 235 28,184 what will happen TO THE ATOM if electron end up inside the nucleus ( as in quantum tunnelling) ? Jun25-13 03:16 AM Tada Amda 3 600 I'm trying to understand the implications of the double-slit experiment, and I have been considering what QM theory... Jun24-13 12:14 PM Cthugha 13 1,372 Two entangled photons are created via, say SPDC, by striking a single photon on a crystal. The two entangled... Jun24-13 10:53 AM San K 2 493 Does anyone know if data from an actual quantum eraser experiment is freely available anywhere? In particular, I'm... Jun24-13 10:25 AM msumm21 0 353 Hello Everybody. Could two past events result in the same happening? For example: We have observed the "incident A"... Jun24-13 08:39 AM skeptic2 6 745 I am a little confused when it is stated that Schrödinger's equation represents a deterministic evolution of the wave... Jun23-13 10:29 PM nomadreid 4 1,169 I'm studying Shankar's book (2nd edition), and I came across his equation (15.3.11) about spherical tensor operators:... Jun23-13 04:51 PM Bill_K 1 510 I am having trouble getting the kraus matrices(E_k)) from a unitary matrix. This task is trivial if one uses dirac... Jun23-13 04:22 PM Henriamaa 0 439 what is the difference between strong force and residual strong force ?what is its range? Jun23-13 12:02 PM mfb 1 558 I have read the following three simplifications in various places, but together they give a contradiction, so at least... Jun23-13 01:57 AM nomadreid 3 523 I haven't studied quantum physics academically and I have no understanding of it mathematically so forgive me if my... Jun22-13 11:41 PM wotanub 1 476 Hello, The quantum zeno effect is well understood and experimentally confirmed as regards polarization... Jun22-13 10:09 PM strangerep 9 962 I was reading through my Principles of Quantum Mechanics textbook and arrived at the section that discusses the... Jun22-13 11:15 AM Bill_K 6 519 The Hamiltonian is ##H=\hbar \omega (a^\dagger a+b^\dagger b)+\hbar\kappa(a^\dagger b+ab^\dagger)## with commutation... Jun22-13 06:39 AM Bill_K 1 401 Bell theorem say that there is a contradiction between the locality principle in special relativity theory and quantum... Jun22-13 05:46 AM stevendaryl 17 1,616 The vacuum-vacuum expectation value in the absence of a source is in general not equal to 1, but exp, where E is the... Jun21-13 10:36 PM geoduck 3 543 Relativity says photons have energy E=pc. Classical physics says E=1/2 pv. There seems to be a factor of 2 missing... Jun21-13 10:25 PM PBTR3 3 600 I'd like to know if creation and annihilation operators are involved in a free trajectory of a particle from point A... Jun21-13 07:17 PM Simon Bridge 1 418 The average particle energy of a Fermi-Dirac gas, with zero chemical potential, is about 3.15T, where T is the... Jun21-13 01:32 PM Avodyne 5 516 Superposition caused by - Double slit, Mach-Zehnder Quantum superimposed paths/waves interfere ...for example the... Jun21-13 12:39 PM San K 8 1,259 In isolated time evolution, the Schrödinger equation takes one state ψ1 to ψ2. But it does this with certainty, no?... Jun21-13 09:22 AM vanhees71 21 1,030