Work

Theory of nonlinear electron relaxation in thin gold films and their signatures in optical observables

Year: 2025

Type: article

Abstract: Based on the momentum-resolved Boltzmann equation, we provide self-consistent numerical calculations of the dynamics of conduction electrons in thin noble metal films after linear and nonlinear optical excitations with infrared and terahertz frequencies. Focusing exclusively on electron-phonon interaction, orientational relaxation is introduced and acts as dephasing of the optical excitation on a scale of tens of fs. In the linear regime, our numerical results agree with the field-strength-independent orientational relaxation rate and correspondingly fits of experimental data to a Drude model and predict for nonlinear excitations a field-strength-dependent increase of the orientational relaxation rate. In the THz regime, where the orientational relaxation proceeds faster than the oscillation cycle of the excitation THz field, a new high-order dissipative Kerr-type nonlinearity is predicted. This nonlinearity originates from the Pauli blocking included in the electron-phonon scattering and results in a nonlinearly increasing transmission of the film, detectable in experiments.

Source: Physical review. B./Physical review. B

DOI: 10.1103/7w9j-88zg

Authors: Jonas Grumm, Malte Selig, Holger Lange, Andreas Knorr

Institutions: Technische Universität Berlin, University of Potsdam

Language: English

Topic: Laser-Matter Interactions and Applications

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: Deutsche Forschungsgemeinschaft, Technische Universität Wien, Technische Universität Berlin, Deutsches Elektronen-Synchrotron

Award: Plasmonkontrolle mit THz Pulsen