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Qutrit
A qutrit (comes from: quantum trit) is the quantum mechanical version of a trit, and has thee basis states, ket 0, ket 1 and ket 2. You write it as
|0⟩, |1⟩ and |2⟩
Explanation
That looks a lot like the numbers 0, 1 and 2, which you can store in a trit. A trit has a value of 0 or 1 or 2 but not all these values simultaneously.
A qutrit is a unit of quantum information. Superposition enables multiple qutrits to express different strings. So can e.g. four qutrits have the value 1020 as well as the value 2102.
Note
A qutrit can be displayed as an othogonal combination of the three basic states
|ψ⟩ = α |0⟩ + β |1⟩ + γ |2⟩
where α, β and γ are complex probability amplitudes. The probability that a qutrit has a |0⟩ state is |α|^{2}, that it has this |1⟩ state is |β|^{2}, and that it has this |2⟩ state is |γ|^{2}, because
|α|^{2} + |β|^{2}+ |γ|^{2} = 1