Publications de Christian Reinhard Ast

Long- versus Short-Range Scattering in Doped Epitaxial Graphene

Klaus Kern, Christian Reinhard Ast, Carola Strasser

Tuning the electronic properties of graphene by adatom deposition unavoidably introduces disorder into the system, which directly affects the single-particle excitations and electrodynamics. Using angle-resolved photoemission spectroscopy (ARPES) we trace ...

Amer Chemical Soc2015

Origin of Rashba splitting in the quantized subbands at the Bi2Se3 surface

Klaus Kern, Christian Reinhard Ast

We study the band structure of the Bi2Se3 topological insulator (1 1 1) surface using angle-resolved photoemission spectroscopy. We examine the situation where two sets of quantized subbands exhibiting different Rashba spin splitting are created via bendin ...

Amer Physical Soc2013

Assessing the atomic contribution to the Rashba spin-orbit splitting in surface alloys: Sb/Ag(111)

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Luca Moreschini

We have studied the electronic structure of the Ag(111)(root 3x root 3)R30 degrees-Sb surface alloy by angle-resolved photoemission. We find two hybrid surface bands, similar to the isostructural Ag(111)-Bi interface. The spin-orbit coupling induced spin s ...

2009

Influence of the substrate on the spin-orbit splitting in surface alloys on (111) noble-metal surfaces

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Luca Moreschini

We have studied by angle-resolved photoelectron spectroscopy the ordered XCu2 surface alloys formed by X=Sb and Bi on a Cu(111) substrate. We found clear analogies with the corresponding XAg2 alloys formed by the same elements on Ag(111). The electronic st ...

2009

Silicon Surface with Giant Spin Splitting

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Emmanouil Frantzeskakis

We demonstrate a giant Rashba-type spin splitting on a semiconducting substrate by means of a Bi-trimer adlayer on a Si(111) wafer. The in-plane inversion symmetry is broken inducing a giant spin splitting with a Rashba energy of about 140 meV, much larger ...

American Physical Society2009

Electronic structure of an ordered Pb/Ag(111) surface alloy: Theory and experiment

Marco Grioni, Christian Reinhard Ast, Daniela Pacilè, Luca Moreschini

We have studied by angle-resolved photoelectron spectroscopy (ARPES) the band structure of the ordered surface alloy obtained by the deposition of 0.33 monolayers of Pb on the Ag(111) surface. We observe several dispersing features which are well described ...

2006

Photoemission as a probe of coexisting and conflicting periodicities in low-dimensional solids

Helmuth Berger, Marco Grioni, Luca Perfetti, Christian Reinhard Ast, Daniela Pacilè

When two different periodic potentials are present at the same time in a solid, the electron wavefunctions must conform to the resulting overall periodicity. It is the case of the broken-symmetry phases which are often observed in low-dimensional systems. ...

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2005