Researchers break a fundamental rule of optics using simple semiconductor nanoclusters

Cornell researchers found that simple semiconductor nanoclusters can break optical reciprocity, making light behave differently depending on viewing direction.

Using cadmium-based magic-size clusters, they combined linear dichroism and chiral dichroism to create films with direction-dependent optical responses.

The approach offers a simpler, lower-cost alternative to complex metamaterials or magnetic-field-based methods for nonreciprocal photonics.

The work could enable new designs for holography, optical encryption, and photonic circuits.