Contact: Dr. Marco Grioni

Team spring 2004

ARPES view of the metal-insulator Mott transition in the layered material 1T-TaSe2.

High-resolution spectroscopies of strongly correlated and low-dimensional materials

Understanding the electronic origin of macroscopic physical properties is a prerequisite to design new materials tailored to specific applications. In Lausanne, and at synchrotron radiation laboratories worldwide, we investigate the effects of electronic correlations, electron-phonon interactions, and confinement in solids by high energy electron and x-ray spectroscopies.

Angle-resolved photoemission (ARPES) with very high energy resolution gives us a uniquely detailed view of the elementary electronic excitations in low-dimensional metals, high-Tc superconductors, heavy fermions, artificial nanostructures. It also reveals the often subtle changes associated with electronic instabilities, like charge-density-wave or Mott metal-insulator transitions. This powerful approach has instigated similar efforts within MaNEP, and is complementary to other optical, transport and magnetic studies.

We are also involved (at ESRF - Grenoble) in the development of novel spectroscopies like high-resolution photoemission with hard x-rays, and resonant inelastic x-ray scattering (RIXS) which provide truly bulk-sensitive information, namely in materials under high pressure. With J. Mesot (PSI) and in partnership with the Swiss Light Source, we have proposed the ADRESS soft x-ray beamline, which will be one of the most advanced instruments for the spectroscopy of solids.