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

TL;DR

This paper demonstrates how to manipulate the terahertz response of liquids by controlling polaron excitations with a pump field, creating a 'polar impostor' that mimics different systems' optical properties.

Contribution

It introduces a novel method to tune polaron frequencies in liquids using quantum control techniques, experimentally realizing the theoretical concept of polar impostorons.

Findings

Polaron frequency can be controlled by a pump field.

Different liquids can be made to have identical polaron responses.

Experimental evidence supports the feasibility of polar impostorons.

Abstract

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, rendering the polaron frequency of three different liquids identical. The experiments demonstrate the feasibility of 'polar impostorons', a so far purely theoretical phenomenon.