Ferroelectric Domain Control of Nonlinear Light Polarization in MoS2 via PbZr0.2 Ti0.8 O3 Thin Films and Free-Standing Membranes.

Two-dimensional transition metal dichalcogenides (TMDCs) such as MoS2 exhibit exceptionally strong nonlinear optical responses, while nanoscale control of the ampltiude, polar orientation, and phase of the nonlinear light in TMDCs remains challenging. In this work, by interfacing monolayer MoS2 with epitaxial PbZr0.2 Ti0.8 O3 (PZT) thin films and free-standing PZT membranes, we report the modulation of the amplitude and polarization of the second harmonic generation (SHG) signal via ferroelectric domain patterning, and demonstrate that PZT membranes can lead to in-operando programming of nonlinear light polarization. The coupling between the MoS2 polar axis with either the out-of-plane polar domains of PZT or the in-plane polarization of domain walls tailors the SHG light polarization into different patterns with distinct symmetries, which has been modeled via nonlinear electromagnetic theory. Our study provides a new material platform that enables reconfiguratable design of light polarization at the nanoscale, paving the path for developing novel optical information processing, smart light modulator, and integrated photonic circuits. This article is protected by copyright. All rights reserved.