Tuning the terahertz response of liquids by creating polar many-body excitations

A surprising result from the theory of quantum control is the degree to which the properties of a physical system can be manipulated. Both atomic and many-body solid-state models admit the possibility of creating a “driven imposter” in which the optical response of one material mimics that of a dynamically distinct system. Here we apply these techniques to polarons in polar liquids. Such quasiparticles describe solvated electrons interacting with many-body degrees of freedom of their environment. The polaron frequency, which depends on the electron concentration in the liquid, is controlled with a pump field. Using this field as a control, we demonstrate the aforementioned dynamical mimicry experimentally, rendering the polaron frequency of three different liquids identical.