Physical Review A

Spatially and temporally controlling electron spin polarization in strong-field ionization using orthogonal two-color laser fields

Meng Han, Peipei Ge, Mingming Liu, Qihuang Gong, Yunquan Liu

Published Feb 4, 2019• 18 citations

Abstract

We propose a scheme to produce spatially and temporally controlled spin-polarized photoelectrons by strong-field ionization of atoms. We calculate the momentum-resolved electron spin polarization from two spin-orbit coupled ionic states ($J=1/2$ and $J=3/2$) of krypton atoms in orthogonal two-color laser fields using the strong-field approximation, and obtain the instantaneous spin-polarization degree. With this scheme, the spin-up and -down photoelectrons can be well separated in the space, and the spin polarization is controlled on the sub-laser-cycle timescale. This study illustrates and reveals the mechanism of the generation of spin-polarized photoelectrons with an arbitrary spatially and temporally tailored laser field. We expect this work has implications for controlling the spatiotemporal spin polarization in strong-field physics.

DOI: 10.1103/physreva.99.023404

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Physical Review A

Spatially and temporally controlling electron spin polarization in strong-field ionization using orthogonal two-color laser fields

Meng Han, Peipei Ge, Mingming Liu, Qihuang Gong, Yunquan Liu

Published Feb 4, 2019• 18 citations

Publisher

Abstract

J=1/2

and

J=3/2

) of krypton atoms in orthogonal two-color laser fields using the strong-field approximation, and obtain the instantaneous spin-polarization degree. With this scheme, the spin-up and -down photoelectrons can be well separated in the space, and the spin polarization is controlled on the sub-laser-cycle timescale. This study illustrates and reveals the mechanism of the generation of spin-polarized photoelectrons with an arbitrary spatially and temporally tailored laser field. We expect this work has implications for controlling the spatiotemporal spin polarization in strong-field physics.

DOI: 10.1103/physreva.99.023404

Related papers

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J=1/2

and

J=3/2

We study the control of ionization dynamics of aligned

{\mathrm{N}}_{2}

and

{\mathrm{O}}_{2}

molecules in orthogonally polarized two-color (OTC) fields and calculate the photoelectron momentum distributions of molecules by solving the time-dependent Schr\"odinger equation and with a semiclassical model. In contrast with that of atoms in the OTC field, we show that the photoelectron momentum distribution is essentially dependent on the molecular outmost orbital, the alignment angle, and the phase of the OTC field. We illustrate the controlling of the molecular frame photoelectron angular distributions and the temporal and spatial double-slit interference effect for strong-field ionization of

{\mathrm{N}}_{2}

molecules. For

{\mathrm{O}}_{2}

molecules, it is shown that the ionization wave packets are splitting. The temporal and spatial double-slit interference effect is always present for

{\mathrm{O}}_{2}

, which is not able to be turned off using the OTC field. This work would have implications for probing molecular structures with a two-color synthesized laser field.

p

-orbital channels. When intermediate-state dynamics become significant, the torus develops a clear splitting. These results establish photoelectron spin textures as a complementary source of dynamical information beyond conventional momentum spectroscopy, and identify spin polarization as a robust internal degree of freedom for self-referenced attosecond metrology.