Virtual electromagnetic absorption and energy storage by a Hermitian system via complex frequency excitation

Hermitian systems, with no Ohmic loss, support virtual absorbing modes located in the complex frequency plane. Although being usually considered non-physical due to their divergent exponential time dependence, these modes play a crucial role in the overall scattering response. Here, we access these modes and use them for virtual absorption and storage of light by specifically shaping the incident excitation with exponentially growing envelopes.