Recent content by randomquestion

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    Physical explanation of energy shift in Heisenberg term in t-J model

    Thank you very much for your reply! When you say 'capturing the correct energetics,' do you mean ensuring the proper singlet-triplet splitting (where the singlet is lower in energy)?
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    Physical explanation of energy shift in Heisenberg term in t-J model

    I'm reading "Lecture Notes on Electron Correlation and Magnetism" by P. Fazekas, and I came across a question regarding the form of the Heisenberg term in the t-J model. In Chapter 5.1.4, the t-J model is written where there is an additional density-density term in the exchange interaction...
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    Reproduce band structure Kagome Fermi-Hubbard using Python

    thank you
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    Reproduce band structure Kagome Fermi-Hubbard using Python

    Hello, thank you all for the replies. I found the source of my error. I have wrongly defined the K point. It should be: # high symmetry points Gamma = np.array([0, 0]) K = 2*np.pi*np.array([1/3, 1/np.sqrt(3)]) M = 2*np.pi*np.array([0, 1/(np.sqrt(3))]) with this convention we get the correct...
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    Reproduce band structure Kagome Fermi-Hubbard using Python

    We need to define a high symmetry point path in the Brillouin zone, we can choose: Gamma-K-M-Gamma My attempt: import numpy as np import matplotlib.pyplot as plt # lattice vectors a1 = np.array([1, 0]) a2 = np.array([-1/2, np.sqrt(3)/2]) a3 = -(a1 + a2) a = [a1,a2,a3] #high symmetry points...
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    Fourier transform of t-V model for t=0 case

    To compute the Fourier transform of the ##t-V## model for the case where ##t = 0##, we start by expressing the Hamiltonian in momentum space. Given that the hopping term ##t## vanishes, we only need to consider the potential term: $$\hat{H} = V \sum_{\langle i, j \rangle} \hat{n}_i \hat{n}_j$$...