2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96896Motivated by magnetization studies of the "telephon number compound" Sr_14Cu_24O_41 we investigate doped Heisenberg spin rings by means of complete numerical diagonalization of a Heisenberg Hamiltonian that depends parametrically on hole positions. A comparison with experimental magnetization data reveals rather accurate information about the screened electrostatic interaction between the charged holes on the ring which appears to be astonishingly strong.3 pages, 2 figures, submitted to JMMMStrongly Correlated ElectronsMaterials Sciencetext