Beyond-dipole approximation effects in photoionization: importance of the photon momentum

In most of the past studies of processes involving interaction of lasers with atoms and molecules the tiny photon momentum has not been taken into account nor the issue of momentum sharing between a photoelectron and an ion has not been addressed despite the fact than when intense lasers are used a huge amount of infrared photons are absorbed. This situation has been related to the fact that in most theoretical investigations the dipole approximation has been used for description of the photoionization processes. In this talk I emphasize the importance of using the non-dipole approaches in description of the interaction of intense lasers with atoms and molecules. I will review some surprising results obtained by us using numerical solutions of the time-dependent Schroedinger equation in [1-3] and present new results related to the photon-momentum effect using counter-propagating pulses and the specific non-dipole effects in diatomic molecules. [1] S. Chelkowski, A.D. Bandrauk, and P.B. Corkum, Phys.Rev.Let. 113, 263005 (2014). [2] S. Chelkowski, A.D. Bandrauk, and P.B. Corkum, Phys.Rev. A 92, 051401 (R) (2015). [3] S. Chelkowski, A.D. Bandrauk, and P.B. Corkum, Phys.Rev. A 95, 053402 (2017).Non UBCUnreviewedAuthor affiliation: Université de SherbrookeOthe