Direct Measurement of Ballistic and Diffusive Electron Transport in Gold

Authors

Pravin Karna, University of Rhode Island
Md Shafkat Hoque, Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States.
Sandip Thakur, University of Rhode Island
Patrick E. Hopkins, Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States.
Ashutosh Giri, University of Rhode Island

Document Type

Article

Date of Original Version

1-25-2023

Abstract

We experimentally show that the ballistic length of hot electrons in laser-heated gold films can exceed ∼150 nm, which is ∼50% greater than the previously reported value of 100 nm inferred from pump-probe experiments. We also find that the mean free path of electrons at the peak temperature following interband excitation can reach upward of ∼45 nm, which is higher than the average value of 30 nm predicted from our parameter-free density functional perturbation theory. Our first-principles calculations of electron-phonon coupling reveal that the increase in the mean free path due to interband excitation is a consequence of drastically reduced electron-phonon coupling from lattice stiffening, thus providing the microscopic understanding of our experimental findings.

Publication Title, e.g., Journal

Nano letters

Volume

23

Issue

2

Citation/Publisher Attribution

Karna, Pravin, Md S. Hoque, Sandip Thakur, Patrick E. Hopkins, and Ashutosh Giri. "Direct Measurement of Ballistic and Diffusive Electron Transport in Gold." Nano letters 23, 2 (2023). doi: 10.1021/acs.nanolett.2c03781.