Xingdong
Reputation
Next privilege 250 Rep.
 Oct 20 awarded Commentator Oct 20 awarded Scholar Oct 20 awarded Supporter Jul 22 awarded Nice Question Mar 1 awarded Famous Question Dec 13 comment Greiner or Landau for Math major student? Can I say that if I mainly consult this 2 series, then I do not really need to use like Goldstein, Jackson for "main-reading" anymore ? (Maybe just occasionally for some pages in library) (And physics is not core research for me after all, though it is important and often related for my research field) Dec 13 comment Greiner or Landau for Math major student? Thanks for the advice. Yeah, I agree that it is necessary to consult many resources, one of main purpose here is to select a "main" good resource for personal collection and serious study, then it is ok to use the library for filling the gaps. Dec 13 asked Greiner or Landau for Math major student? Oct 20 accepted Solution of dynamics of density matrix Sep 24 awarded Autobiographer Aug 22 comment Stabilization of von Neumann equation Thank you very much. Now I understand. By the way, is it called stationary state in physics ? Aug 22 comment Stabilization of von Neumann equation I agree with it that for the closed quantum system it will endlessly oscillate. Well, I'd like to know if it is possible to explicitly to show $[H, \rho(0)]\neq 0$ in your proof of the form of expansion of density operator above, i.e. $$\rho(t) = \sum_{m,n} \rho_{mn}(0) e^{-iHt}\lvert m\rangle\langle n\rvert e^{-iHt} = \sum_{m,n} \rho_{mn}(0) e^{-i(E_m-E_n)t}\lvert m\rangle\langle n\rvert = \sum_{m,n} \rho_{mn}(t) \lvert m\rangle\langle n\rvert,$$ Aug 22 comment Stabilization of von Neumann equation Yes, and in the solution function graph the fluctuation of the curve to be smaller and smaller as time to infinity. The point is not against the proof with the eigenstates, but the place where we can use the condition that $H$ and $\rho(0)$ does not commutes, since the the form above can always be shown even if $[H, \rho(0)]=0$ Aug 21 comment Stabilization of von Neumann equation Thank you for the solution. But I am not very sure where it was used the condition $[H, \rho(0)]\neq 0$ to prove that the solution $\rho(t)$ will be stabilized, where it is not related to the zero derivative, since there can be small fluctuation even with large derivative. Aug 16 accepted Prove the solution of von Neumann equation will never stabilize if Hamiltonian and initial density matrix commutes Aug 16 comment Prove the solution of von Neumann equation will never stabilize if Hamiltonian and initial density matrix commutes @yuggib It means the density matrix will never approach the steady state. Aug 16 revised Prove the solution of von Neumann equation will never stabilize if Hamiltonian and initial density matrix commutes added 53 characters in body Aug 16 revised Prove the solution of von Neumann equation will never stabilize if Hamiltonian and initial density matrix commutes deleted 1 character in body Aug 16 asked Prove the solution of von Neumann equation will never stabilize if Hamiltonian and initial density matrix commutes Jun 3 accepted Derivation of a quantum dynamical map on open quantum system