Quantum computing represents one of the most consequential technological frontiers of the twenty-first century, promising to revolutionise fields ranging from cryptography and materials science to logistics optimisation and drug discovery. A detailed feature in The Hindu examines the current state of global quantum computing research and highlights the significant hardware limitations that continue to separate the promise of quantum computing from practical, everyday performance — a gap directly relevant to India’s ambitious ₹6,000 crore National Quantum Mission (NQM), sanctioned by the Union government in April 2023.
This topic is critical for India’s technological and strategic future because quantum computing threatens to disrupt existing cryptographic systems that secure everything from banking transactions to national defence communications, while simultaneously offering transformative capabilities in simulating molecular structures for pharmaceutical research and optimising complex systems such as power grids and financial markets. India’s positioning in this global race — as a rule-maker or as a technology-taker — will significantly influence its digital sovereignty and economic competitiveness by the early 2030s.
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For UPSC and SSC aspirants, this topic is a prime example of an emerging science and technology theme that regularly appears in both preliminary and mains examinations, testing candidates’ understanding of both the underlying scientific principles and their policy implications for India’s innovation ecosystem.
Background and Context
Quantum mechanics, the branch of physics governing matter and energy at atomic and subatomic scales, differs fundamentally from classical mechanics in that particles can exist in multiple states simultaneously — a phenomenon called superposition — and can become correlated regardless of physical distance, known as entanglement. These two properties form the theoretical foundation of quantum computing, first conceptualised by physicist Paul Benioff in 1980 and later advanced by scientists including Richard Feynman, David Deutsch, and Peter Shor.
Five Important Key Points
- India’s National Quantum Mission, sanctioned with an outlay exceeding ₹6,000 crore in April 2023, aims to build intermediate-scale quantum computers and position India among leading nations in quantum technology development by 2031.
- Google Quantum AI’s 2024 breakthrough, published in the journal Nature, demonstrated for the first time that increasing the number of physical qubits in a lattice configuration from 3×3 to 7×7 suppressed the encoded error rate by a factor of two, addressing quantum computing’s central challenge of noise and errors.
- Contemporary quantum processors have error rates between 0.1% and 1%, meaning one in every 100 to 1,000 quantum operations results in an error, compared to classical computers where errors occur roughly once in every quintillion operations.
- Quantum computers utilise diverse hardware architectures, including superconducting qubits (used in Google’s Willow processor), trapped-ion qubits, photonic qubits, and nuclear magnetic resonance (NMR) qubits, each with distinct advantages and engineering challenges.
- Industry experts, including Google Quantum AI spokespersons, caution that no quantum computer has yet demonstrated a commercially relevant problem that cannot also be solved by classical supercomputers, underscoring that practical quantum advantage remains a future milestone rather than a present reality.
The Science Behind Quantum Advantage
Classical computers process information using bits that exist definitively as either 0 or 1. Quantum computers use qubits, which can exist in superposition — simultaneously representing 0, 1, and every state in between — dramatically expanding computational parallelism. When combined with entanglement, where the state of one qubit instantaneously affects another regardless of distance, quantum computers theoretically gain the ability to solve certain classes of problems, particularly those involving large-scale optimisation and molecular simulation, exponentially faster than classical machines.
The Noise Problem and Error Correction
The central engineering challenge, as detailed extensively in the article, is that qubits are extraordinarily fragile and prone to “decoherence” — losing their quantum properties through interaction with the environment. This necessitates extreme isolation, including cooling systems that bring qubits to temperatures near absolute zero (-273°C). Scientists address this through quantum error correction, which combines multiple physical qubits into a single, more reliable “logical qubit.” Google’s Willow processor demonstrated that this approach can work at scale, marking a significant milestone towards what researchers call “fault-tolerant quantum computing.”
India’s Strategic Position and Applications
Indian researchers, including those at IIT-Madras and the Indian Institute of Science, are actively working on quantum materials, devices, and algorithms under the NQM framework. Potential applications with direct relevance to India include optimising India’s complex logistics and transportation networks, modelling climate systems for more accurate monsoon prediction, securing digital communications against future quantum-enabled decryption threats (a concern given India’s Digital Public Infrastructure), and accelerating drug discovery for diseases prevalent in India.
Global Competitive Landscape
The United States, through companies like Google and IBM, along with China and the European Union, have made aggressive investments in quantum computing. Google expects to demonstrate a long-lived, error-corrected logical qubit within the next five years, while IBM has targeted 2029 for a fault-tolerant quantum computer. India’s NQM, while significant by domestic standards, remains modest compared to the scale of investment by leading global players, raising questions about whether India can develop indigenous quantum hardware capability or will remain primarily dependent on foreign quantum infrastructure and cloud-based quantum computing access.
Way Forward
India should prioritise building specialised quantum talent through dedicated postgraduate and doctoral programmes, given that quantum engineering requires interdisciplinary expertise spanning physics, computer science, and materials engineering. Strategic partnerships with global quantum leaders for technology transfer, while simultaneously building indigenous manufacturing capability for critical quantum hardware components, would reduce long-term dependency. India must also urgently develop post-quantum cryptography standards to protect critical infrastructure and digital public goods like Aadhaar and UPI from future quantum decryption risks, a task requiring close coordination between the Ministry of Electronics and Information Technology and national security agencies.
Relevance for UPSC and SSC Examinations
This topic falls under GS-III (Science and Technology, indigenisation of technology, developments in emerging technologies) for UPSC Mains, and is a recurring theme for UPSC Prelims current affairs and SSC General Awareness sections. Key terms to remember: National Quantum Mission (2023), qubit, superposition, entanglement, decoherence, quantum error correction, superconducting/trapped-ion/photonic qubits, and fault-tolerant quantum computing.