Revealing a full quantum ladder by nonlinear spectroscopy

TL;DR

This paper introduces a three-pulse laser spectroscopy method to explore high-level quantum excitations and anharmonicities, enabling detailed mapping of quantum systems beyond traditional two-quanta excitation limits.

Contribution

It proposes a novel spectroscopy approach that allows scanning of nonlinear potential surfaces at arbitrary excitation levels, revealing full quantum ladders.

Findings

Enables evaluation of high-level anharmonicities.

Allows direct measurement of transition amplitudes.

Addresses quantum nature through peak position analysis.

Abstract

Coherent two-dimensional spectroscopy in IR or visible region is very effective for studying correlations, energy relaxation/transfer pathways in complex multi-chromophore or multi-mode systems. However it is usually restricted up to two-quanta excitations and their properties. In this paper an arbitrary level of excitation is suggested as the utility to scan nonlinear potential surfaces of quantum systems up to a desired excitation degree. This can be achieved by a simple three-pulse laser spectroscopy approach. Accurate evaluation of high-level anharmonicities as well as transition amplitudes can be directly obtained. Additionally, questions regarding the quantum nature of the probed system can be addressed by studying absolute peak positions.