RRI research push to quantum tech applications

Quantum optics researchers from India and France have provided experimental evidence that confirms the co-existence of wave- and particle-like properties of a single photon. They said findings from the study could stimulate quantum technology applications.

Researchers from the Raman Research Institute (RRI) and their collaborators in the Bose Institute and CY Cergy Paris University in France said the first-of-its-kind study held potential to challenge Neil Bohr’s wave particle complementarity principle, which is critical to the standard quantum interpretation.

Professor Urbasi Sinha, head, Quantum Information and Computing Lab at RRI.

The principle formulated by Bohr, in 1927, holds that experiments on atomic and subatomic systems cannot simultaneously display properties of particles and waves. 

Professor Urbasi Sinha, head, Quantum Information and Computing Lab at RRI, and the corresponding author of the paper, said the experiment demonstrated the “remarkable display of spatial separation between two distinct properties”, that is, polarisation and spatial degrees of freedom of a single photon. The result could have a far-reaching impact on technologies like quantum communications and quantum sensing, she said.

The paper was published in the journal Communications Physics on Tuesday.

Alice in Wonderland 

The researchers argued that the experiment provides an “unambiguous empirical vindication” of the Quantum Cheshire Cat effect, which refers to the separation of an object from its properties. The naming of the effect is inspired from the cat in Alice in Wonderland which, even after disappearing, leaves its grin behind.

The experiment was conducted by PhD students Surya Narayan Sahoo, Sanchari Chakraborti and Saumya Ranjan Behera at RRI, with theory support from Som Kanjilal, Alexandre Matzkin, co-author of the paper and a CNRS Research Professor in theoretical physics at CY Cergy Paris University, and Dipankar Home, co-author and a NASI-Senior Scientist Platinum Jubilee Fellow at the Bose Institute.