ObsidianVault/SS2026/Quantum Computing/6. Composite Systems/Composite Systems.md

Compose different systems with each other

Constructing composite systems

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This definition applies to probabilistic and quantum systems.

Example:

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So to apply S to A and T to B we apply SxT to AB.

If the distribution of a probabilistic system can be written as a composite A and B are independent If we cannot they are depended on each other

If the quantum state of a system AB can be written as a tensor product they are independent If we cannot the quantum states depend on each other, we call this entangled~

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Measuring composite systems

We can compose two separate measurements similarly to how we applied the tensor product.