A new material can force light to spin in a circle without using any external magnets.
April 23, 2026
Original Paper
Localized Exciton Emission with Spontaneous Circular Polarization in NiPS3/WSe2 Heterostructures
arXiv · 2604.17409
The Takeaway
Circularly polarized light is usually created by passing light through a strong magnetic field or a specialized crystal. This new heterostructure combines a semiconductor with a thin layer of magnetic material to do it spontaneously. The internal magnetic field of the material is strong enough to dictate the spin of the light being emitted. This effect occurs naturally at the interface where the two layers meet. Eliminating the need for bulky external magnets could make optical sensors and quantum devices much smaller. This technology could lead to light-based computer chips that process information using the twist of a photon.
From the abstract
Two-dimensional (2D) van der Waals (vdW) heterostructures (HSs) provide a versatile platform for tailoring electronic, optical, and magnetic properties via proximity effects at their interfaces. In this work, we explore the optical response of few-layer NiPS3/WSe2 HSs using low-temperature micro-photoluminescence ({\mu}-PL) and magneto-PL spectroscopy. The HSs exhibit multiple sharp excitonic peaks that do not appear in the individual constituent materials, indicating the emergence of localized