Quanfluence Raises $10 Million to Build a Full-Stack Photonic Quantum Computer in India

Quanfluence, a Bengaluru-based quantum computing start-up incubated at IIT Madras, has raised $10 million (about ₹92 crore) to build what it describes as a full-stack photonic quantum computer, a machine that uses particles of light rather than supercooled circuits to perform calculations.

The round, announced on 7 October, was led by Chiratae Ventures, with participation from Rainmatter, the investment arm of brokerage Zerodha, and existing backer Pi Ventures. It is one of the larger early-stage cheques written into Indian quantum hardware and arrives as the government's National Quantum Mission begins to pull start-ups, research labs and state-backed hubs into a common effort.

The company plans to spend the money bringing together the three layers it is building in-house: indigenously designed photonic chips, the control electronics that run them, and the software that lets users program the system. It is targeting its first early processors by 2027, followed by larger and more scalable machines by 2029.

Selling a quantum-inspired machine while building the real one

Quanfluence was founded in 2021 by Sujoy Chakravarty, Ravi Mehta, Biman Chattopadhyay, Aditi Vaidya, Anil Prabhakar and Sandeep Goyal. Unlike many deep-tech peers that spend years without revenue, the company has already put a product in customers' hands.

That product is an optical Ising machine, a quantum-inspired system that uses light waves as its computational units. It is built for optimisation problems, the class of task in which a business must find the best answer among an enormous number of combinations, such as routing a delivery fleet, balancing a power grid or allocating capital across a portfolio. The machine can process hundreds of interconnected variables at the same time, and the company claims it is up to 100 times faster than traditional optimisation methods.

Chakravarty told Inc42 that Quanfluence has commercialised the Ising machine in two ways: it sells physical systems outright and offers remote access on a usage-based model. The start-up has sold around three machines so far and is running paid pilots with 10 to 15 corporations.

That revenue line matters. A universal quantum computer, capable of running any quantum algorithm, remains a long-horizon engineering programme. A commercial optimisation product gives the company customers, feedback and some income while the harder machine is built, a model that investors in capital-hungry hardware increasingly prefer.

Ising machines take their name from a model in statistical physics that describes how magnetic spins settle into their lowest-energy arrangement. Many real-world business problems can be translated into the same mathematical form, so a machine that finds low-energy states quickly can, in effect, search for good solutions to scheduling, logistics or portfolio questions. Such systems do not deliver the full power of a universal quantum computer, but they can be useful today for problems where conventional solvers slow down as the number of variables grows.

For corporate buyers, the attraction is practical. A bank, manufacturer or logistics operator can test whether the machine improves on its existing optimisation software without committing to a long research partnership, and Quanfluence gains real workloads against which to benchmark and refine its hardware.

Why light, and why now

Quantum computers are being pursued through several competing physical approaches. Superconducting qubits, favoured by IBM and Google, must be cooled to temperatures colder than deep space. Trapped-ion systems hold individual atoms in electromagnetic fields. Photonic systems, the route chosen by Quanfluence and by international players such as PsiQuantum and Xanadu, encode information in photons travelling through chips.

The appeal of photonics is that light-based chips can, in principle, operate closer to room temperature and be produced using techniques borrowed from the established semiconductor and telecommunications industries. The difficulty lies in generating, steering and detecting single photons with low enough losses to make large systems reliable.

Quanfluence says it has made steady progress on those problems since its last fundraise. In December 2024 it raised $2 million (about ₹16.7 crore) in a seed round led by Pi Ventures. Since then it has designed and fabricated multiple photonic integrated circuits and electronic integrated circuits, developed low-loss chip-to-fibre coupling designs and demonstrated the generation of quantum light states.

The company's stated ambition is to scale its architecture from prototypes to systems with millions of qubits. That is a goal shared by every serious quantum hardware effort and achieved by none so far, and the start-up's founders have been candid that the immediate obstacles are practical rather than theoretical: integrating components, scaling manufacturing, and working through the long production cycles of custom chips and hardware.

A busy month for Indian quantum

The funding adds to a run of activity in India's quantum sector. In September, quantum cybersecurity company QNu Labs raised ₹200 crore (about $21 million) in a Series A1 round co-led by the National Quantum Mission and Speciale Invest. Days before Quanfluence's announcement, Bengaluru's QpiAI borrowed ₹50 crore through non-convertible debentures from InnoVen Capital, a rare venture-debt deal in the sector.

The National Quantum Mission, approved by the Union Cabinet in April 2023 with an outlay of about ₹6,003 crore through 2030-31, aims to develop intermediate-scale quantum computers with 50 to 1,000 physical qubits within eight years, across platforms including photonics. Start-ups such as Quanfluence are expected to play a central role in meeting that goal, alongside the IITs and other research institutions anchoring the mission's thematic hubs.

For investors, the bet is that India can build a domestic supply of quantum hardware rather than depend entirely on imported systems, at a time when the technology is increasingly treated as strategically sensitive. Quanfluence currently employs 25 people and expects to grow to about 40 over the next year.

The investor line-up is itself telling. Chiratae Ventures, one of India's longer-standing venture firms, has historically backed technology companies across consumer and enterprise markets; leading a quantum hardware round marks a move deeper into frontier technology. Rainmatter, funded by Zerodha's founders, has increasingly used its capital to support long-gestation bets in climate, health and science. Pi Ventures, which led the seed round, is one of the few Indian funds that focuses specifically on deep technology, and its decision to invest again suggests the company has hit the milestones it set out two years ago.

Their participation reflects a broader shift. Indian venture capital has historically been weighted towards software and consumer internet businesses, where products can be built quickly and scaled cheaply. Hardware-heavy fields such as semiconductors, space and quantum demand patient capital and specialised technical judgement, and a growing number of domestic funds now appear willing to supply both.

The road from a working optical Ising machine to a scalable universal quantum computer is long, and many well-funded companies around the world are attempting the same journey. But with paying customers, a clear hardware roadmap and investors who have backed it twice, Quanfluence has given itself a credible place in that race.