Virtual exceptional points in an electromechanical system (1708.02352v2)

Abstract: Non-Hermitian Hamiltonians can give rise to exceptional points (EPs) which have been extensively explored with nominally identical coupled resonators. Here a non-Hermitian electromechanical system is developed which hosts vibration modes that differ massively in their spatial profile, frequency and even the sign of their dissipation. An optomechanical-like parametric modulation is employed to dynamically couple 2 of these disparate modes and in the appropriate parameter regime their imaginary eigenvalues coalesce whilst their normal modes split. The presence of this virtual EP is confirmed via numerical simulations of the coupled equations of motions describing the dynamics of this non-degenerate system. These results suggest that virtual EPs can be accessed in systems composed from highly mismatched resonators whilst still maintaining access to the non-trivial phenomenon in their proximity, as recently demonstrated for topological operations, thus enabling non-Hermitian singularities to be more widely exploited with realistic physical systems.