I have been trying to simulate the average number of particles at 3 sites of coupled harmonic oscillators. I have used the code from the below tutorial: https://notebook.community/ajgpitch/qutip-notebooks/examples/trilinear I have modified the Hamiltonian as the following with decay parameters gamma being zero.
My Hamiltonian has two parts. Initial Hamiltonian and driving hamiltonian. The driving Hamiltonian is given as following: $H_{0}=\Omega(b_{1}^{\dagger}+b_{2}^{\dagger}+b_{3}^{\dagger})+\Omega^{*}(b_{1}+b_{2}+b_{3})$
I have modified the qutip tutorial of Trilinear oscillators to the form above mentioned Hamiltonian. As I change the number of Fock states considered N1,N2,N3 from 2,3,4...8 the average number particle at each site would change. They have some weird behavior. Can anyone tell me why the average population changes as we change N? How to choose right N to get the average particle at each site?
My results for different Ns are:
