This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

High harmonic spectroscopy retrieves electronic structure of high-pressure superconductors

High harmonic spectroscopy retrieves electronic structure of high-pressure superconductors
The HHG spectra in high-pressure superconductor H3S. Credit: Institute of Physics

High pressure has revealed surprising physics and created novel states in condensed matter. Exciting examples include near room temperature superconductivity (Tc > 200 K) in high-pressure hydrides such as H3S and LaH10.

Although the superconducting transition temperature of high-pressure superconductors is constantly increasing, the mechanism of superconductivity at such high pressures remains an open question. Knowledge of the properties and ultrafast dynamics of electrons and quasiparticles in high-pressure quantum states is lacking.

High harmonic generation (HHG) is the up-conversion of laser light to radiation carried at multiples of the laser frequency. HHG in solids originates from the nonlinear driving of electrons within and between electronic bands by strong field light-matter interactions. Therefore, HHG spectroscopy naturally contains fingerprints of intrinsic atomic and electronic properties of materials. There is a great deal of excitement in learning about material properties through this nonlinear, non-perturbative laser-matter interaction.

Using state-of-the-art first-principles time-dependent density-functional theory simulations, Prof. Meng Sheng's group from the Institute of Physics of the Chinese Academy of Sciences has studied the ultrafast HHG dynamics in the high-pressure superconductor H3S.

  • High harmonic spectroscopy retrieves electronic structure of high-pressure superconductors
    Band structure reconstruction via HHG spectra. Credit: Institute of Physics
  • High harmonic spectroscopy retrieves electronic structure of high-pressure superconductors
    Electron-phonon coupling reconstruction via HHG spectra. Credit: Institute of Physics

The researchers found that HHG in high-pressure superconductors is strongly dependent on the electronic structures and (EPC). The study, titled "Solid-state high harmonic spectroscopy for all-optical band structure probing of high-pressure quantum states," is published in PNAS.

Using HHG spectroscopy, they retrieved the band dispersion and EPC, and revealed the significant influence of the many-body EPC on the electron behavior near the Fermi level.

Their results support the phonon-mediated mechanism based on the EPC of high-pressure superconductivity, providing an all-optical approach to probe the band dispersion and EPC of high-pressure quantum states.

More information: Shi-Qi Hu et al, Solid-state high harmonic spectroscopy for all-optical band structure probing of high-pressure quantum states, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2316775121

Citation: High harmonic spectroscopy retrieves electronic structure of high-pressure superconductors (2024, February 2) retrieved 16 April 2024 from https://phys.org/news/2024-02-high-harmonic-spectroscopy-electronic-pressure.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Ultrafast dynamics of topological material probed under pressure

14 shares

Feedback to editors