Bell States
The Bell states are four states that can be created when two qubits are maximally entangled. The four states are:
IBM Quantum Composer: https://quantum.ibm.com/composer/
1. Phi Plus State
\(\ket{\Phi^+} = \frac{\ket{00} + \ket{11}}{\sqrt{2}}\)

2. Phi Minus State
\(\ket{\Phi^-} = \frac{\ket{00} - \ket{11}}{\sqrt{2}}\)

3. Psi Plus State
\(\ket{\Psi^+} = \frac{\ket{01} + \ket{10}}{\sqrt{2}}\)

4. Psi Minus State
\(\ket{\Psi^-} = \frac{\ket{01} - \ket{10}}{\sqrt{2}}\)
