Sayonee Ray

Hi Daniel, Thanks much for the file. This works fine. Following the earlier numbering: 3) I was thinking of tracking the difference between 4-point correlations like, < a^\dagger _i a_j a^\dagger_k a_l>, and the spdm < a^\dagger _i a_j> (2-point correlations) as a function of time. This is to see how far mean field approximations work. A couple of good things to get some heads up in this comparison might be where: a) all i,j,k,l are different. b) i=j, k=l or something of this kind. c) three of them...

Hi Daniel, Thanks much for your patience and the detailed reply. I really appreciate it. And apologies for the delay in getting back. 1) As for the version, mine is OpenMPSv3. 2) Symmetries: Yes, I want to have number conservation. In that case, I presume I have to put the entry "use_symmetry =True" in the beginning of the code? I have attached the code here. If I do that, I am getting the error message as follows: Traceback (most recent call last): File "initial_state_BH.py", line 160, in <module>...

Hi Daniel, Thanks for the reply. Yes, let me write the question more clearly. The first question: PART I 1) The system is initialized in a density wave represented as a state vector \psi (0) = |0, 1, 0, 1, 0, 1....> , such that only lattice sites with an even (or odd) site index are occupied (by bosons). 2) Next, I want to time evolve this state with the Bose-Hubbard model Hamiltonian. 3) Plot correlation functions like <n> and <nn> as a function of time.</nn></n> For this, I need to construct the...

Hi Daniel, Thanks for your reply. Your suggestion works. I am now trying to play around with the code, exploring different quantities that can be calculated. I do have a few additional questions: 1) In the file BoseHubbardDynamics, I want to customize the time range, i.e, plot 'n' for longer times, or change 'dt' of the time evolution. How do I do that? 2) Given some initial state, I want to time evolve the state with the BH hamiltonian and calculate some observable as a function of time (like, n)....

Hi Daniel, I have downloaded the OpenMPS package and the other necessary libraries required to run the codes. I want to see the correlation functions and expectation value of number density as a function of time in the code BoseHubbardDynamics.py. Could you suggest where exactly I need to make the changes and what should be added? I presume it should be in the paragraph just below the text "Postprocessing and Plotting"? -Best, Sayonee