# Math 401, Paper 1, Side note 1: Quantum information theory and Measure concentration

Shannon theory provides a way to quantify the amount of information in a message.

Practically speaking:

- A holy grail for error-correcting codes
- Conceptually speaking:
- An operationally-motivated way of thinking about correlations
- What’s missing (for a quantum mechanic)?
  - Features from linear structure:
    - Entanglement and non-orthogonality

## MM space
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