抄録
Coherent light-matter interaction drives a variety of interesting processes in a quantum system. Rabi
oscillation is one such process offering a periodic population transfer between quantum states in an
ultrashort time scale. Here we demonstrate a robust and simple scheme to achieve femtosecond twophoton
Rabi oscillations by intense NIR laser pulses, using excited He atoms prepared by EUV-FEL.
The extension to multiphoton regime will expand the applicability to highly excited or dipole-forbidden
states.
