  We propose a numerically exact method for a mixture with a single impurity
immersed in several majority fermions, confined in a harmonic potential. We
separate one of the degrees of freedom through an appropriately tailored
canonical transformation and perform exact diagonalization on the simplified
Hamiltonian. This method is especially effective for a heavy impurity, where it
outmatches the typical exact diagonalization approach. We used our method to
calculate energy and density profiles of the first few eigenstates for the
mixture with up to ten majority fermions.
