Abstract
We improve on Fourier transforms (FTs) between imaginary time and imaginary frequency used in certain quantum cluster approaches using the Hirsch-Fye method. The asymptotic behavior of the electron Green’s function can be improved by using a “sum-rule” boundary condition for a spline. For response functions a two-dimensional FT of a singular function is required. We show how this can be done efficiently by splitting off a one-dimensional part containing the singularity and by performing a semianalytical FT for the remaining more innocent two-dimensional part.
- Received 8 September 2010
DOI:https://doi.org/10.1103/PhysRevB.82.233104
©2010 The American Physical Society