Temperature-Induced Lifshitz Transition and Possible Excitonic Instability in ZrSiSe

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Nodal-line semimetals exhibit unique electronic structures with linear dispersion.
• These materials show vanishing density of states near nodal points.
• Understanding their electronic behavior is crucial for novel electronic applications.

Purpose of the Study:

• Investigate temperature-dependent transport properties of the nodal-line semimetal ZrSiSe.
• Explore the electronic structure using scanning tunneling microscopy/spectroscopy (STM/STS).
• Identify the underlying mechanisms responsible for observed electronic anomalies.

Main Methods:

• Performed temperature-dependent electrical transport measurements on ZrSiSe.
• Utilized scanning tunneling microscopy and spectroscopy (STM/STS) for atomic-scale electronic analysis.
• Conducted theoretical analyses to interpret experimental results.

Main Results:

• Observed distinct transport anomalies in ZrSiSe at 80 K and 106 K.
• Identified temperature-induced Lifshitz transitions at these critical temperatures.
• Measured a V-shaped dip structure in STS spectra near the Fermi energy at low temperatures.

Conclusions:

• The observed Lifshitz transitions and transport anomalies are linked to temperature effects in ZrSiSe.
• The V-shaped dip in STS spectra suggests a combined influence of spin-orbit coupling and excitonic instability.
• Correlation interactions likely play a significant role in the quasi-two-dimensional electronic structure of ZrSiSe.