Berlin 2018 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 12: Ultrafast Electron and spin dynamics at interfaces II

O 12.2: Talk

Monday, March 12, 2018, 15:15–15:30, MA 005

Ultrafast dynamics in bilayer MoS₂ — •Klara Volckaert¹, Søren Ulstrup¹, Charlotte E. Sanders¹, Jill A. Miwa¹, Deepnarayan Biswas², Cephise Cacho³, Paulina Majchrzak³, Igor Marković², Federico Andreatta¹, Adam Wyatt³, Marco Bianchi¹, Sanjoy K. Mahatha¹, Luca Bignardi⁴, Daniel Lizzit⁴, Paolo Lacovig⁴, Silvano Lizzit⁴, Phil D. C. King², and Philip Hofmann¹ — ¹Aarhus University, Aarhus, Denmark — ²University of St Andrews, St Andrews, UK — ³Central Laser Facility, Didcot, UK — ⁴Elettra Sincrotrone Trieste, Trieste, Italy

The recent development of ultrafast time-resolved photoemission experiments has led to novel findings concerning non-equilibrium electron dynamics. Of particular interest are the 2D semiconducting transition metal dichalcogenides (TMDCs) that can be seen as graphene analogues with strong spin-orbit interactions. Here, the ultrafast dynamics of bilayer MoS₂ on Ag(111) are investigated using time and angle resolved photoemission spectroscopy (TR-ARPES) following an optical excitation with tunable polarisation. Curiously, we find that the nature of the light polarisation dependence for excitation between the valence and conduction bands is different from what would be naively expected on the basis of valley-selection rules. Our results could provide new insight into the interlayer coupling and inter-valley dynamics at play in bilayer TMDCs.