Fig. 3: Decay of off-diagonal elements of transformed Hamiltonian.
From: Hamiltonian transformation for accurate and efficient band structure interpolation
a Decay properties of the m-banded Hermitian matrix H after transformation, ∣fa,n(H)ij∣ ≤ ca,nF[fa,n, k], mk < ∣i − j∣ ≤ m(k + 1), ca,n is a factor normalizes F[fa,n, 0] to 1. We emphasize that the results apply to all m-banded Hermitian matrices. b, c show similar decay behavior as in (a), but with the transition region width a set to 0.5 and 0.25, respectively.
