Author(s): Zheng, F (Zheng, Fan); Wang, LW (Wang, Lin-wang)

Source: PHYSICAL REVIEW LETTERS Volume: 131 Issue: 15  Article Number: 156302  DOI: 10.1103/PhysRevLett.131.156302  Published: OCT 10 2023 

Abstract: With the rapid development of ultrafast experimental techniques for the research of carrier dynamics in solid-state systems, a microscopic understanding of the related phenomena, particularly a first-principle calculation, is highly desirable. Nonadiabatic molecular dynamics (NAMD) offers a real-time direct simulation of the carrier transfer or carrier thermalization. However, when applied to a periodic supercell, there is no cross-k-point transitions during the NAMD simulation. This often leads to a significant underestimation of the transition rate with the single-k-point band structure in a supercell. In this work, based on the surface hopping scheme used for NAMD, we propose a practical method to enable the cross-k transitions for a periodic system. We demonstrate our formalism by showing that the hot electron thermalization process by the multi-k-point NAMD in a small silicon supercell is equivalent to such simulation in a large supercell with a single Gamma point. The simulated hot carrier thermalization process of the bulk silicon is compared with the recent ultrafast experiments, which shows excellent agreements. We have also demonstrated our method for the hot carrier coolings in the amorphous silicons and the GaAlAs2 solid solutions with the various cation distributions.

Accession Number: WOS:001102939300005

PubMed ID: 37897744

Author Identifiers:

Author Web of Science ResearcherID     ORCID Number

Zheng, Fan       0000-0002-6497-6198

Wang, Lin-Wang      0000-0001-7061-2692

ISSN: 0031-9007

eISSN: 1079-7114