Ultrafast dynamics in photoexcited Bismuth surface and bulk states
Event details
| Date | 11.06.2012 |
| Hour | 12:15 |
| Speaker | Evangelos Papalazarou, Laboratoire de Physique des Solides, UMR 8502, Université Paris Sud, Orsay, France |
| Location | |
| Category | Conferences - Seminars |
The structure of the A7 compounds may be described as a distorted simple cubic structure, where the (111) planes of atoms have an alternating displacement along the (111) direction. In one dimension, this type of distortion is well known as Peierls distortion [1]. Bismuth is an A7 semimetal where Peierls instability causes a symmetry breaking along the trigonal (111) direction. Due to this distorted nature of the ground state photo‐induced excitation of valence electrons increases the electronic density in the conduction band thereby reducing the energy gain of the Peierls distortion. This renders the Peierls distortion unstable and a phase transition towards an undistorted phase stands possible within a timescale inferior to that required for the electron‐phonon coupling thermalization.
Practical information
- Informed public
- Free
Organizer
- ICMP
Contact
- Dr Barbara Mansart