Quantum Supremacy

Quantum Supremacy Latest News

Researchers from the University of Oxford and Universidad de Sevilla demonstrated quantum supremacy through a simple mathematical game, published in Physical Review Letters.

What is Quantum Supremacy?

• Quantum supremacy refers to the ability of a quantum computer to solve a problem that classical computers cannot solve efficiently.
• It marks a milestone in quantum computing, proving that quantum machines can outperform classical computers for certain specific tasks.
• Demonstrating quantum supremacy has been a long-standing challenge due to the complexity of designing problems that showcase this advantage in an unambiguous and easily verifiable way.

The Quantum Supremacy Game 

• The game is based on the "odd-cycle graph colouring problem":
  • Can you colour a circle with an odd number of sections using only two colours, such that no two adjacent sections share the same colour?
  • Mathematically, this is impossible in classical terms for any odd-numbered cycle.
• It uses only two entangled qubits, making the setup far simpler than earlier quantum supremacy demonstrations.
• Google’s 2019 experiment used random circuit sampling on its Sycamore processor with 53 superconducting qubits, which required massive computational resources. 
• China’s Jiuzhang quantum computer used Gaussian boson sampling, again demanding complex tools and mathematics.
• In contrast, this new game-based method is minimalist yet powerful, demonstrating clear quantum advantage with far fewer resources.

Quantum vs Classical Computing

• Classical Computers operate on bits (0 or 1) and rely on classical physics.
• Quantum Computers work on qubits, which can exist in superposition — being 0 and 1 at the same time.
• Qubits also exhibit entanglement, where the state of one qubit instantly affects another, regardless of distance.

Superposition and Entanglement:

• Superposition allows a quantum processor to perform many computations simultaneously.
• Entanglement creates non-classical correlations, which are central to quantum communication, cryptography, and computation.

Power of Qubits

• As the number of qubits increases, the computational capacity increases exponentially compared to classical bits.
• For instance, a 50-qubit quantum processor can potentially outperform the fastest classical supercomputer.

Quantum Supremacy FAQs

Q1. What is quantum supremacy?
Ans. Demonstrated when a quantum computer solves a problem infeasible for classical computers (e.g., Google’s 2019 Sycamore processor).

Q2. Why is it strategic for India?
Ans. Critical for cryptography, drug discovery, and AI. India’s National Quantum Mission (2023) allocates ₹6,000 crore for R&D by 2031.

Q3. Which Indian institutions lead quantum research?
Ans. IISc Bengaluru, TIFR Mumbai, and IIT Madras’ Centre for Quantum Information, Communication, and Computing.

Q4. What are the key challenges?
Ans. Error rates in qubits, scalability issues, and high costs (₹100+ crore per advanced quantum computer).

Source: TH