# Quantum computing for the very curious

# # Quantum computing for the very curious

Metadata

CiteKey:: matuschakQuantumComputingVery2019Type:: webPageAuthor::Andy Matuschak,Michael NielsenYear:: 2019Tags:: #ðŸ“¥Source/Zotero, #on/Quantum-Computing, #on/Mnemonic-MediumFormat:: PDF

Abstract

Presented in an experimental mnemonic medium that makes it almost effortless to remember what you read

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Keywords:: Quantum Computing, ðŸ“¥

Notes

- The state of a qubit is a vector in a two-dimensional vector space.
- $|0 \rangle$ and $|1 \rangle$ are
computational basis states.- A Superposition is a linear combination of $|0 \rangle$ and $|1 \rangle$.
- An
amplitudeis the coefficient for a particular state in superposition.- All quantum states are normalized.
- The Quantum State of a qubit is a vector of unit length in a two-dimensional complex vector space known as state space. ^bdb050
- Quantum Gate
- Quantum state of any system is not directly observable.
- To extract information from a quantum system, we use a process called Measurement in the computational basis.
- All quantum gates are unitary matrices
- Unitary matrices preserve the length of their inputs $U^\dagger U = I$.
Global phase factors have no impact on the results of the computation.

## # Extracted Annotations

In natural science, Nature has given us a world and weâ€™re just to discover its laws. In computers, we can stuff laws into it and create a world.

â€”â€‰Alan Kay

The theory of computation has traditionally been studied almost entirely in the abstract, as a topic in pure mathematics. This is to miss the point of it. Computers are physical objects, and computations are physical processes. What computers can or cannot compute is determined by the laws of physics alone, and not by pure mathematics.

â€”â€‰David Deutsch