Tomio Hashimoto

Dear Daniel, Thank you for the advise. I can now calculate the density matrix between an impurity and the next sites, but I'm not 100% sure which basis they are given. Let us suppose that the local Hilbert space is spanned by a basis {| u >, | d >}. So the (1,1)-component of a local operator O is < u | O | u >, and (2,2)-component is < d | O | d >. Is the density matrix for sites [i,j] given by {|uu>,|ud>,|du>, |dd>}, or {|uu>,|du>,|ud>, |dd>}, or other ordering of the Schmidt basis? Since I have...

Dear Daniel, Thank you for the advise. I can now calculate the density matrix between an impurity and the next sites, but I'm not 100% sure which basis they are given. Let us suppose that the local Hilbert space is spanned by a basis {|u>, |d>}. So the (1,1)-component of a local operator O is <u|o|u>, and (2,2)-component is <d|o|d>.</d|o|d></u|o|u> Is the density matrix for sites [i,j] given by {|uu>,|ud>,|du>, |dd>}, or {|uu>,|du>,|ud>, |dd>}, or other ordering of the Schmidt basis? Since I have...

Dear Daniel, Thank you for the advise. I can now calculate the density matrix between an impurity and the next sites, but I'm not 100% sure which basis they are given. Let us suppose that the local Hilbert space is spanned by a basis {|u>, |d>}. So the (1,1)-component of a local operator O is <u|o|u>, and (2,2)-component is <d|o|d>.</d|o|d></u|o|u> Is the density matrix for sites [i,j] given by {|uu>,|ud>,|du>, |dd>}, or {|uu>,|du>,|ud>, |dd>}, or other ordering of the Schmidt basis? Since I have...

Hi all, I'm trying to simulate an impurity problem, and wondering if I can just calculate local observables such as local population, and currents between the impurity and the rest. It costs a lot to calculate correlation functions between all the L sites , but I only need a few of them. I appreciate if you can help me how to do this. Maybe we can use DensityMatrix_ij? Best,

Hi Daniel, I'm sorry for the late reply. I have been traveling last week. Thank you so much for the exmaple codes! I want to try an initial guess like |20202020...>, so the implementation is good enough for me. I agree that the naive speed-up may not be achieved with initial guess, since it depends on specifics of the simulations. I also agree that when next-nearest neighbor repultion is infinite, there are many degenerate ground states. I was imagining the case when we can map the model to a Heisenberg...

Hi Daniel, Thank you for the response, and I will try the odd system size to see the CDW phase. And it would be really nice that we can give an initial gues. This my be also useful for sweeping in a phase space; we can use the ground state of similar parameters as an initial guess to acheive faster convergence (especially near the phase boundary). Best,

Hallo, I'm looking into the extened Bose Hubbard model with filling n =1. My problem is that I cannot get the correct symmetry-broken ground state. When the neaest-neighbot interaction V is strong, I would expect that the ground state looks like {202020....2020}, while the one I got is {2020...20020202.....0202}; there is always a kink in the middle. I believe that this is due to the construction of the warm-up process. Can we give some initial guess to the ground state serach, so that we are not...