The Midas touch: Reflections on J.F. McGilp's role in elucidating the properties of Si(111)-Au and Si(hhl)-Au using RAS

Gold-stabilized Si(111) has long attracted the interest of top surface scientists. Besides being a prototypical metal-semiconductor interface, Si(111)-Au exhibits-- along with its vicinal Si(hhl)-Au family--unique quasi-1D structural and electronic properties that continue to drive top-class research to this day [1]. Although Prof. McGilp made key early contributions to the field, including optical second harmonic studies [2], STM [3], ARPES [4], and spectroscopic ellipsometry [5], this presentation will focus on his more recent investigations using reflectance anisotropy spectroscopy (RAS) of nominal and vicinal Si(111)-Au to deduce the atomic structure, step morphology, and role of Si and Au coverage, first using phenomenological arguments [6,7,8] and more recently in collaboration with theoreticians [9,10,11]. The presentation will conclude with some recent theoretical interpretations of Prof. McGilp's measured spectra on Si(775)-Au [12] and some of the latest developments in the field regarding RAS studies on Si(hhl)-Au [12,13]. [1] J. Aulbach et al, Nano Lett, 16 2698 (2016); idem, Phys. Rev. Lett. 111 137203 (2013); S. Erwin and F. Himpsel, Nat. Commun. 1 58 (2010) [2] J.F.McGilp Semi. Sci. Tech. 2 102 (1987); J.D. O'Mahony, P.V. Kelly and JF McGilp 56--58 449 (1992) [3] J.D. O'Mahony, C.H. Patterson, J.F. McGilp, et al Surf. Sci. Lett. 277, L57 (1992) [4] I.R. Collins,.., JF McGilp et al, Surf. Sci. 325 45 (1995) [5] J.D. O'Mahony, JF McGilp, Appl. Surf. Sci. 63 266 (1993); J.D. O'Mahony, J.F. McGilp et al, Surf. Sci. 365 801 (1996) [6] J. Jacob, J.F. McGilp et al, phys stat sol (c) 5 2569 (2008) [7] N. McAlinden and J. F. McGilp, EPL 92, 67008 (2010) [8] N. McAlinden and J. F. McGilp J. Phys.: Cond. Mat 21, 474208 (2009) [9] C. Hogan, N. McAlinden, J. McGilp, Phys Stat Sol B 249, 1095-1104 (2012) [10] C Hogan, E Ferraro, N McAlinden, JF McGilp, Phys. Rev. Lett. 111, 087401 (2013) [11] CH Patterson, S Banerjee, JF McGilp, Phys Rev B 94, 165417 (2016) [12] C. Braun, S. Sanna, WG Schmidt, C. Hogan, E. Speiser, S. Chandola, N. Esser (in preparation) [13] C. Hogan, E. Speiser, S. Chandola, S. Suchkova, , J. Aulbach, J. Schafer, S. Meyer, R. Claessen and N. Esser (submitted)