EPR pairs

• $|{\beta }_{00}⟩=\frac{|00⟩+|11⟩}{\sqrt{2}}$
• $|{\beta }_{01}⟩=\frac{|01⟩+|10⟩}{\sqrt{2}}$
• $|{\beta }_{10}⟩=\frac{|00⟩-|11⟩}{\sqrt{2}}$
• $|{\beta }_{11}⟩=\frac{|01⟩-|10⟩}{\sqrt{2}}$