Spin-resolved off-normal photoemission from xenon adsorbates in comparison with free-atom photoionization

Abstract

Circularly polarized synchrotron radiation of BESSY has been used to study the angular dependence of the spin polarization of photoelectrons emitted from X e (~x 1~) R30 ° Pd(lli). The spin-polarization component along the light helicity varies from + 1 for normal emission to -0 . 5 for emission angles larger than 45 ° . The data can be fitted by use of the theory for photoionization of free xenon atoms and yield the dynamical fit parameters A, ~,/~, ~ for the adsorbate. Good agreement is obtained with the gas phase data.

Spin–orbit-induced photoelectron spin polarization in angle-resolved photoemission from both atomic and condensed matter targets

“…It is surprising how accurate the photoemission results in the condensed matter follow the atomic model and the data for gaseous atomic xenon. This is quantitatively supported by the cross-comparison of the spin polarization component perpendicular to the reaction plane P ⊥ which is valid also for photoemission with unpolarized radiation for a certain photoelectron emission angle 30 • (figure 18) for the xenon adsorbate system and free xenon atoms [46] and shows excellent agreement. Figures 17 and 18 demonstrate that the spin polarization defined as…”

“…Figure 17 shows in cross-comparison the angular dependence of the spin polarization component P(θ ) parallel to the light helicity within the reaction plane for atomic photoionization of xenon and the corresponding experimental results for the photoemission from a commensurate xenon monolayer adsorbed on Pd (111) as a function of the emission angle for different photon energies including fitted curves according to equation (1) [46]. It is surprising how accurate the photoemission results in the condensed matter follow the atomic model and the data for gaseous atomic xenon.…”

“…The data can be fitted within the atomic model not only for the primary photoemission process but also for the subsequent Auger decay process emitting spin polarized Auger electrons due to the decay of a spin polarized photohole state [47]. Photoelectron emission of inner core (111)] at different photon energies [46]. Adapted from [46].…”

“…Photoelectron emission of inner core (111)] at different photon energies [46]. Adapted from [46]. 17; open squares: free Xe atoms [46].…”

“…17; open squares: free Xe atoms [46]. From [46]. shells and valence bands create holes which are generally spin-oriented as the emitted photoelectrons.…”