Light-induced renormalization of the Dirac quasiparticles in the nodal-line semimetal ZrSiSe

TL;DR

This study demonstrates that optical excitation can transiently reduce electronic correlations in the nodal-line semimetal ZrSiSe, enabling all-optical control of its band structure through ultrafast screening effects.

Contribution

It introduces an all-optical method to manipulate the electronic correlations and band structure in a nodal-line semimetal using ultrafast photoexcitation.

Findings

Electronic correlations are reduced on ultrashort timescales by optical excitation.

Transient screening of Coulomb interactions alters the electronic structure.

The method enables all-optical control of quantum material properties.

Abstract

In nodal-line semimetals linearly dispersing states form Dirac loops in the reciprocal space, with high degree of electron-hole symmetry and almost-vanishing density of states near the Fermi level. The result is reduced electronic screening and enhanced correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time- and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT +U +V). We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.