Communications in Theoretical Physics
Tunable giant Kerr nonlinearity-driven photonic spin–orbit interaction in an N -coupled quantum dot system
Akhtar Munir, Muhib Ullah, Chunfang Wang
Abstract
Abstract The Photonic spin Hall effect (PSHE) offers fundamental insights into spin–orbit interactions of light, yet its control over compact, tunable platforms remains a challenge. Here, we investigate the PSHE in a solid-state platform of N -coupled quantum dots (CQDs), focusing on both the linear absorption and Kerr nonlinear regimes. On this platform, an external electric field controls electron tunneling between CQDs, resulting in multiple tunneling-induced transparency windows. We report a giant enhancement of the Kerr nonlinearity, achieving orders-of-magnitude increases while suppressing linear absorption—a domain that is favorable for low-power nonlinear photonics. Exploiting this, we demonstrate that the PSHE shift can be drastically enhanced and controlled by tuning the excited-state transition frequency and tunneling strengths, which significantly modify the Brewster angle. This active nonlinear control improves static nanostructures by combining the tunability of atomic systems with the functionality of an integrable quantum material. Our results establish N -CQDs as a viable platform for producing giant Kerr nonlinearity-driven PSHE, opening up new possibilities for tunable low-power spin–orbit light control in quantum photonics.