Spin-resolved strong-field dynamics have recently emerged as a frontier in ultrafast and nonlinear optics, with growing evidence that spin effects can critically influence strong-field phenomena. Motivated by experimental observations of potassium atoms in atomic ionization in strong laser fields, where a characteristic photoelectron peak appears to exhibit an angular distribution related to the $m_l=1$ component, we solve the time-dependent Schrödinger equation including explicit spin-orbit coupling (SOC). Our calculations qualitatively reproduce the reported photoelectron momentum distribution and the characteristic peak, providing direct theoretical support for SOC-induced features in strong-field resonant multiphoton ionization. We show that the Autler-Townes splitting manifests as Rabi oscillations between the $S$ ground state and the resonant $P$ intermediate state, while the SOC further splits the dynamics into two phase-opposed Rabi oscillations between the $S$ and $P_{1/2}/P_{3/2}$ states, whose gradual dephasing during the electronic evolution gives rise to the characteristic peaks and directly links the yields to the SOC-induced level splitting. By unifying experimental observations, ab initio simulations, and a transparent Rabi-based framework, this work provides a coherent and physically intuitive understanding of spin-resolved strong-field ionization dynamics.

Close

PrevNext

View figure in article

• Spin-orbit coupling
• Strong field ionization & excitation
• Ab initio calculations