The photoemission spectra for Mott insulating surfaces

Adolfo Trumper

Instituto de Fisica Rosario, CONICET (Argentina), Bv. 27 de Febrero 210, bis, Argentina

We show theoretically the fingerprints of short range spiral magnetic correlations in the photoemission spectra of the Mott insulating ground states realized in the √3 X √3 triangular silicon surfaces K/Si(111)-B and Sic(0001). The calculated spectra present low energy features of magnetic origin with a reduced dispersion ∼ 10-40 meV compared with the centre-of -mass spectra bandwidth ∼ 0.2-0.3 eV. Remarkably, we find that the quasiparticle signal survives only around the magnetic Goldstone modes. Our findings position these silicon surfaces as new candidates for investigation in the search for non-conventional quasiparticle excitations.