My main research interest is the physics of low-dimensional systems. This includes three aspects: (i) the synthesis of nanostructures, (ii) the manipulation of samples on the nanometer-scale, and (iii) their characterization with spatially resolved spectroscopic techniques.
Stefan Heun received his diploma in Physics in 1989 from the University of Hannover (Germany), where he investigated, in the group of Prof. M. Henzler, the initial stages of epitaxial growth of silicon on Si(100). In 1993 he received his Ph.D. in the same group, working on the magnetoconductivity of monolayer-thin films of Ag, Pb, and Au deposited on Si(111).
In 1993 he joined the Interdisciplinary Research Laboratories of the Japanese Telecom NTT in Tokyo (Japan), where he studied the surface passivation of III-V semiconductors using synchrotron radiation.
In 1995 he moved as a TMR Marie Curie research fellow of the Commission of the European Community to the Materials Division of the TASC lab in Trieste (Italy), where he worked on the engineering of heterostructure interfaces.
In 1997 he became a beam line scientist at the Sincrotrone Trieste, where he was appointed responsible of the Nanospectroscopy Beamline, at which he also performed his research on the properties of low-dimensional systems.
Finally, in 2004 he joined the INFM-CNR as a senior scientist, first at TASC in Trieste and since October 2006 at NEST in Pisa (Italy). In these last years his work focuses on the use of scanning probe microscopies for the spectroscopic study of nanostructures.
S. Heun, B. Radha, D. Ercolani, G. U. Kulkarni, F. Rossi, V. Grillo, G. Salviati, F. Beltram, and L. Sorba: Coexistence of Vapor-Liquid-Solid and Vapor-Solid-Solid growth modes in Pd-assisted InAs nanowires, Small 6 (2010) 1935 - 1941.
N. Paradiso, S. Heun, S. Roddaro, L. N. Pfeiffer, K. W. West, L. Sorba, G. Biasiol, and F. Beltram: Selective control of edge-channel trajectories by scanning gate microscopy, Physica E 42 (2010) 1038 - 1041.
V. Baranwal, G. Biasiol, S. Heun, A. Locatelli, T. O. Mentes, M. N. Orti, and L. Sorba: Kinetics of the evolution of InAs/GaAs quantum dots to quantum rings: A combined x-ray, atomic force microscopy, and photoluminescence study, Phys. Rev. B 80 (2009) 155328.
J. T. Robinson, F. Ratto, O. Moutanabbir, S. Heun, A. Locatelli, T. O. Mentes, L. Aballe, and O. Dubon: Gold-catalyzed oxide nanopatterns for the directed assembly of Ge island arrays on Si, Nano Letters 7 (2007) 2655 - 2659.
Th. Schmidt, J. I. Flege, S. Gangopadhyay, T. Clausen, A. Locatelli, S. Heun, and J. Falta: Alignment of Ge nanoislands on Si(111) by Ga-induced substrate self-patterning, Phys. Rev. Lett. 98 (2007) 066104.
F. Ratto, A. Locatelli, S. Fontana, S. Kharrazi, S. Ashtaputre, S. K. Kulkarni, S. Heun, and F. Rosei: Diffusion dynamics during the nucleation and growth of Ge/Si nanostructures on Si(111), Phys. Rev. Lett. 96 (2006) 096103.
A. Locatelli, C. Sbraccia, S. Heun, S. Baroni, and M. Kiskinova: Energetically driven reorganization of a modified catalytic surface under reaction conditions, J. Am. Chem. Soc. 127 (2005) 2351 - 2357.