In this paper we derive and discuss the completely spin- and photon-polarization-dependent probability rates for nonlinear Compton scattering and nonlinear Breit-Wheeler pair production. The locally constant field approximation, which is essential for applications in plasma-QED simulation codes, is rigorously derived from the strong-field QED matrix elements in the Furry picture for a general plane-wave background field. We discuss important polarization correlation effects in the spectra of both processes. Asymptotic limits for both small and large values of $\chi$ are derived and their spin and polarization dependence is discussed.

• Received 28 July 2020
• Accepted 28 September 2020

DOI:https://doi.org/10.1103/PhysRevA.102.052805