ObsidianVault/SS2026/Quantum Computing/14. Quantum Computer/From Quantum Physics to Quantum Computers.md

We now look at the construction of a single-qubit quantum computer (hypothetical):

We encode the qubit using the excitation of an electron. We assume that an electron has only states \ket{0} and \ket{1} with 0 being the ground state. The states have energy levels \pi and 2\pi.

Now we need to be able to do 3 things:

1. Initialize qubit with \ket{0}, also called cooling.
2. Ability to measure the qubit.
3. Ability to apply a unitary to qubit.

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