India’s Quantum Frontier: IISc Unveils 6‑Qubit Photonic Computer Built with Packets of Light

India has crossed a critical threshold in the global quantum race with scientists at the Indian Institute of Science (IISc), Bengaluru, unveiling the country’s first six‑qubit photonic quantum system. Developed under the National Quantum Mission, the setup uses photons packets of light to encode and process quantum information, placing India in an exclusive club of nations pursuing quantum computing through light‑based platforms rather than solely through superconducting or ion‑trap systems.​

At the heart of the system is an elegant idea: use different degrees of freedom of a single photon, such as its path and polarization, to encode multiple qubits, thereby achieving a six‑qubit entangled Greenberger–Horne–Zeilinger (GHZ) state using only two photons. The IISc team has experimentally realized universal quantum gates and entanglement in a programmable “quantum walk” architecture, moving beyond earlier probabilistic photonic schemes by demonstrating deterministic gate operations that boost reliability and scalability.​

Photons offer several natural advantages for quantum technology: they are inherently resistant to environmental noise, can travel long distances in optical fibers, and can operate at or near room temperature, which sharply contrasts with the extreme cooling required for many superconducting systems. However, photons rarely interact with each other, making it difficult to implement the multi‑qubit gates needed for computation—a challenge the IISc architecture addresses by cleverly using multiple degrees of freedom of each photon and engineered interference.​

The current six‑qubit device is not a general‑purpose quantum computer but a crucial testbed. Even at smaller qubit counts, such systems can already power practical tools like quantum random number generators for cryptography and secure key distribution, areas where the team and broader Indian ecosystem are actively building hardware and protocols. As the architecture scales from six to twelve qubits and beyond, it is expected to enable proof‑of‑concept demonstrations in quantum simulation, optimization, and secure communication networks.​

This milestone also reflects the growing ambition of India’s National Quantum Mission, which aims to build indigenous capabilities across hardware, software, and applications. By investing in diverse platforms—including photonics, superconducting qubits, and atomic systems—the country is building a broad knowledge base that future researchers and startups can extend into deep‑tech products in areas such as materials discovery, pharmaceuticals, and advanced AI. As Prof. Chandrashekhar and peers emphasize, the most transformative applications of quantum computing may be those that today’s generation cannot yet fully imagine, but will emerge once robust, scalable quantum processors become reality.​​

Source: “India’s Quantum Frontier: 6‑Qubit Photonic System – Prof. C.M. Chandrashekhar,” Ones Changing The World