Tailoring $\mathcal{P}\mathcal{T}$-symmetric soliton switch

We theoretically demonstrate soliton steering in $\mathcal{P}\mathcal{T}$-symmetric coupled nonlinear dimers. We show that if the length of the $\mathcal{P}\mathcal{T}$-symmetric system is set to $2\pi$ contrary to the conventional one which operates satisfactorily well only at the half-beat coupling length, the $\mathcal{P}\mathcal{T}$ dimer remarkably yields an ideal soliton switch exhibiting almost 99.99% energy efficiency with an ultra-low critical power.