The equivalent two-level system (IMAGE)

Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS

The equivalent two-level system

Caption

a, The original spin-1/2 setting describing spinnings of a quantum particle in a driven magnetic field, where the spin up and spin down constitute the two-level eigenstates. b, In the presented setting, the eigenstates R and L simultaneously coupling with the SAM and OAM are defined as the spin up and spin down equivalents, respectively. These pseudo spin up and spin down states are coupled by a synthetic magnetic field. c, The higher-order Poincaré sphere is introduced to represent the spin-orbit states, with two poles denoting the eigenstates. d, Typical states mapped on the sphere (marked points in c) showing spatial variations of polarization (upper panels) and phase (bottom panels) distributions with polar angle. The arrows in the upper panels denote polarizations; while the black lines in the bottom panels represent the phase contours.

Credit

by Guohua Liu, Xiliang Zhang, Xin Zhang, Yanwen Hu, Zhen Li, Zhenqiang Chen, and Shenhe Fu

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Credit must be given to the creator.

License

CC BY

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