Spin polarization and attosecond time delay in photoemission from spin degenerate states of solids

Abstract

After photon absorption, electrons from a dispersive band of a solid require a finite time in the photoemission process before being photoemitted as free particles, in line with recent attosecondresolved photoemission experiments. According to the Eisenbud-Wigner-Smith model, the time delay is due to a phase shift of different transitions that occur in the process. Such a phase shift is also at the origin of the angular dependent spin polarization of the photoelectron beam, observable in spin degenerate systems without angular momentum transfer by the incident photon. We propose a semi-quantitative model which permits to relate spin and time scales in photoemission from condensed matter targets and to better understand spin- and angle-resolved photoemission spectroscopy (SARPES) experiments on spin degenerate systems. We also present the first experimental determination by SARPES of this time delay in a dispersive band, which is found to be greater than 26 as for electrons emitted from the sp-bulk band of the model system Cu(111).

6 pages, 3 figures

References in corpus (2)

• Energy-dependent photoemission delays from noble metal surfaces by attosecond interferometry
• Decoherence in Attosecond Photoionization

Cited by in corpus (8)

• Rashba spin splitting of L-gap surface states on Ag(111) and Cu(111)
• Spin- and angle-resolved photoemission on topological materials
• Spin-resolved electronic response to the phase transition in MoTe${}_2$
• Determination of the time scale of photoemission from the measurement of spin polarization
• Doping Dependence of Spin-Momentum Locking in Bismuth-Based High-Temperature Cuprate Superconductors
• Visualization of optical polarization transfer to photoelectron spin vector emitted from the spin-orbit coupled surface state
• Dependency of quantum time scales on symmetry
• Impact of a Fano resonance on the measured transition time scale in solid state photoemission