Work

Time-dependent dichroism and transient valley polarisation in monolayer transition metal dichalcogenides under finite-pulse radiation

Year: 2025

Type: article

Abstract: Recent advances in time-resolved angle-resolved photoemission spectroscopy have enabled access to ultrafast electron states and their spin dynamics in solids. Atomically thin transition metal dichalcogenides are paradigmatic two-dimensional materials where electron momentum and spin degrees of freedom are coupled, being suitable candidates for time-resolved spectroscopy studies. In this work, we present a thorough study of the electron dynamics when these materials are subject to an intense finite-pulse driving radiation. We extend the scope of the conventional Floquet engineering and rely on the so-called t − t ′ formalism to deal with driving fields described with two distinct time scales, namely the envelope amplitude timescale and the time period of the external field. The interplay between the finite-pulse timescales and the intrinsic properties of the electrons gives rise to transient valley polarisation and dynamical modifications of band structures, revealed by the time-dependent circular dichroism of the sample.

Source: Journal of Physics Materials

DOI: 10.1088/2515-7639/ade292

Authors: Alejandro S Gómez, Yuriko Baba, Francisco Domínguez-Adame, Rafael A Molina

Institutions: Universidad Complutense de Madrid, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Instituto de Estructura de la Materia

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,745

Funders: Comunidad de Madrid, Agencia Estatal de Investigación