How IISc scientists are bringing quantum tech closer to reality

Bengaluru: Scientists at the Indian Institute of Science (IISc), Bengaluru, are bringing quantum tech closer to reality by developing a cutting-edge platform for controlling light at the nanoscale. Their work has the potential to transform quantum information processing, quantum communication, data encryption, and photonic quantum computing. 

Light is not just something we see; it plays a crucial role in modern technology. From fiber optic internet to lasers in medical treatments, controlling light efficiently is essential. But at the quantum level — where particles of light (photons) behave in strange and fascinating ways — precise control is even more critical. 

In quantum cryptography, for example, information is encoded using individual photons. If we can generate and manipulate these photons, we can create unhackable communication systems. 

The researchers focused on tiny, specially engineered materials called colloidal quantum wells (CQWs), which can emit light at the nanoscale. These CQWs were integrated with structures known as dielectric metasurfaces — engineered surfaces that can manipulate light in novel ways. 

By combining CQWs with these metasurfaces, the team achieved: 12 times brighter light emission and 97% reduction in spectral width, meaning the emitted light is purer and more precise. 

"This study is just the beginning. This platform has potential for future applications like photonic information processing, quantum information processing, basically quantum information processing, but using light, that is why it is called photonic quantum information processing,” said Prof Jaydeep K Basu, the corresponding author of the study. 

The team now plans to integrate single quantum emitters (SPEs) with metasurfaces to create even more efficient single-photon sources. These are essential for advanced quantum cryptography and computing. 

With continued progress, we could see quantum networks enabling completely secure data transmission, ultra-precise sensors for medical and scientific applications, and highly efficient quantum computers — all powered by innovations in controlling light at the nanoscale. 

Prof Basu said, “Our work shows how nanoscale materials can be seamlessly integrated with photonic structures to achieve exceptional control over light emission and transport.”