A study led by the University of Portsmouth has achieved unprecedented precision in detecting tiny shifts in light displacements at the nanoscale. This is relevant in the characterization of birefringent materials and in high-precision measurements of rotations.

The quantum sensing breakthrough is published in the journal Physical Review A, and has the potential to revolutionize many aspects of daily life, industry, and science.

Imagine two photons, massless particles of light, that are intertwined in a unique way, meaning their propagation is connected even when they are separated. When these photons pass through a device that splits the particles of light into two paths—known as a beam-splitter—they interfere with each other in special patterns. By analyzing these patterns, researchers have developed a highly precise method to detect even the tiniest initial spatial shifts between them.