Lesson 267

Quantum Computing

Qubits · Superposition · Entanglement · Real Speedups

1:00

A rigorous yet intuitive tour of qubits, superposition, entanglement, and the specific algorithmic speedups that make quantum computing real.

By the end, you can

  • Write and interpret the qubit state α|0⟩ + β|1⟩ and explain the normalization constraint.
  • Apply the Born rule to compute the probability of each measurement outcome from given amplitudes.
  • Locate |0⟩, |1⟩, and |+⟩ on the Bloch sphere and explain what the equator represents.
  • Describe what measurement does to a qubit and why repeated shots are needed to estimate probabilities.
  • Identify the action of the X, H, Z, and CNOT gates and classify them as single- or two-qubit gates.
  • Explain how H followed by CNOT builds the Bell state, and why it sends no faster-than-light signal.
  • State the speedups Grover and Shor achieve and name the problem each solves.
  • Explain why quantum speedups are problem-specific and what decoherence means for practical hardware.
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