Optical initialization and manipulation of higher-order electron states with spin and orbital angular momentum in a semiconductor quantum disk.

Electrons confined in quantum-disk structures exhibit an intrinsic spin vortex state with spin angular momentum (SAM) and orbital angular momentum (OAM) [Phys. Rev. B79(15), 155450 (2009)10.1103/PhysRevB.79.155450]. A higher-order electron state, which is a SAM - OAM entangled state expressed by superposition of spin-vortex states, has a spatial spin structure and can be represented as a higher-order Bloch vector on a higher-order Bloch sphere [Optica Quantum2(4), 245 (2024)10.1364/OPTICAQ.527615]. In this study, we analyzed the Rabi oscillation of higher-order electron states in a quantum disk structure driven by higher-order photons possessing both SAM and OAM, with the aim of manipulating SAM - OAM entangled electron states. The higher-order Bloch vector precesses about the Stokes vector of the higher-order photon-driven field, and its precession behavior can be controlled by the state of the driving photon field, pulse width, and intensity. These results will lead to the realization of high-dimensional quantum computations and high-dimensional quantum interfaces using SAM and OAM of electrons and photons.