Nonlinear Spectroscopy with X-Ray Two-Photon Absorption in Metallic Copper

Kenji Tamasaku (1) , Eiji Shigemasa (2) , Yuichi Inubushi , Ichiro Inoue (1) , Taito Osaka (1) , Tetsuo Katayama , Makina Yabashi (1) , Akihiro Koide (3) , Toshihiko Yokoyama , Tetsuya Ishikawa (1)

1 RIKEN - RIKEN - Institute of Physical and Chemical Research [Japon]
2 Nagoya University
3 IPR - Institut de Physique de Rennes

X-ray two-photon absorption (TPA) spectrum of metallic copper is measured using a free-electron laser (XFEL). The spectrum differs from that measured by the conventional one-photon absorption (OPA), and characterized by a peak below the Fermi level, which is assigned to the transition to the 3d state. The impact of the XFEL pulse on the OPA spectrum is discussed by analyzing the pulse-energy dependence, which indicates that the intrinsic TPA spectrum is measured.

Domaines: Physique [physics]

Kenji Tamasaku, Eiji Shigemasa, Yuichi Inubushi, Ichiro Inoue, Taito Osaka, et al.. Nonlinear Spectroscopy with X-Ray Two-Photon Absorption in Metallic Copper. Physical Review Letters, 2018, 121 (8), pp.083901. ⟨10.1103/PhysRevLett.121.083901⟩. ⟨hal-01879726⟩