UPSC CSE Prelims
Quantum Computing Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 2 — Quantum Computing

A qubit (quantum bit) is the fundamental unit of information in quantum computing, analogous to the classical bit. Unlike classical bits that exist in either 0 or 1 state, qubits can exist in a superposition of both states simultaneously, enabling quantum computers to perform complex calculations exponentially faster for certain problems.

📝 Short Notes: Quantum Computing Fundamentals

• Qubit (Quantum Bit): The basic unit of quantum information that can exist in superposition of |0⟩ and |1⟩ states simultaneously.
• Superposition: A quantum phenomenon where a qubit exists in multiple states at once until measured, unlike classical bits which are deterministic.
• Quantum Entanglement: Qubits can be entangled such that the state of one instantly affects another, regardless of distance.
• Quantum Gates: Operations that manipulate qubits, analogous to logic gates in classical computing but exploiting quantum properties.
• Decoherence: The main challenge in quantum computing where qubits lose their quantum properties due to environmental interference.
• Applications: Cryptography, drug discovery, optimization problems, artificial intelligence, and financial modeling.
• Major Players: IBM, Google, Microsoft, and various research institutions are developing quantum computers with increasing qubit counts.