4) Two-photon photoemission spectroscopy

Nano-structures fabricated on surface at the atomic scale are expected to have new electronic states different from those in crystalline bulk. The nature would be applied to new functional materials in future. In order to reveal the fundamental properties at surfaces and the excited-states of materials, we have constructed a two-photon photoemission spectroscopy (2PPE) by use of ultrashort laser pulses. Using this spectroscopy, we will investigate not only the electronic states of strongly correlated materials but also the electronic states of adsorbed molecules, which are different from those of bulk crystals.