Temperature-Induced Lifshitz Transition and Possible Excitonic Instability in ZrSiSe

TL;DR

This study reveals temperature-induced Lifshitz transitions and potential excitonic instability in ZrSiSe, highlighting the role of correlation interactions in its electronic properties.

Contribution

It provides experimental evidence of temperature-driven Lifshitz transitions and suggests excitonic effects in ZrSiSe, a nodal-line semimetal.

Findings

Lifshitz transitions occur at 80 and 106 K in ZrSiSe.

A V-shaped dip in STS spectrum indicates excitonic instability.

Transport anomalies coincide with Lifshitz transition temperatures.

Abstract

The nodal-line semimetals have attracted immense interest due to the unique electronic structures such as the linear dispersion and the vanishing density of states as the Fermi energy approaching the nodes. Here, we report temperature-dependent transport and scanning tunneling microscope (spectroscopy) (STM[S]) measurements on nodal-line semimetal ZrSiSe.Our experimental results and theoretical analyses consistently demonstrate that the temperature induces Lifshitz transitions at 80 and 106 K in ZrSiSe, which results in the transport anomalies at the same temperatures. More strikingly, we observe a V-shaped dip structure around Fermi energy from the STS spectrum at low temperature,which can be attributed to co-effect of the spin-orbit coupling and excitonic instability. Our observations indicate the correlation interaction may play an important role in ZrSiSe, which owns the quasi-two-dimensional electronic structures.