Test of an Optimised Exact-Diagonalization Approach for Trapped Fermionic Mixtures

Abstract

We probe the convergence of the configuration interaction (CI) approach for harmonically trapped one-dimensional Fermi–Fermi mixtures. Existing scientific papers that apply the CI approach to study such systems typically use harmonic oscillator eigenfunctions with fixed frequency parameter values as bases. We show that CI’s optimisation is the key to reducing the computational cost of the numerical study of fermionic mixtures. The effectiveness of the optimised CI approach is analysed in terms of its ability to capture the spatial fermion–fermion correlations.