Double-Carrier Fitting of Hall Resistance Assisted by Gate-Induced Shubnikov-de Haas Oscillations in Possible Excitonic Insulator Ta2Pd3Te5

TL;DR

This paper introduces a simplified method for fitting Hall resistance data in Ta2Pd3Te5, an excitonic insulator, using gate-induced Shubnikov-de Haas oscillations to improve accuracy and provide evidence for its excitonic-insulator state.

Contribution

A novel approach reduces the complexity of double-carrier fitting in Hall measurements by leveraging gate-induced oscillations, enhancing reliability in identifying excitonic insulator states.

Findings

Successful double-carrier fitting with a single parameter

Evidence supporting excitonic insulator state in Ta2Pd3Te5

Enhanced accuracy in Hall resistance analysis

Abstract

Hall effect is an important phenomenon when a magnetic field is applied to materials. From the curve depicting the Hall resistance versus the magnetic field, crucial information such as carrier concentration can be extracted. If the curve exhibits a linear dependence up to rather high magnetic fields, it indicates that charge transport involves only a single type of carrier, and if a non-linear curve is measured, then the double-carrier model should be considered for fitting. However, this model involves four unknown parameters, including the concentration and mobility of the two carriers, resulting in that such fitting is usually non-unique, which significantly reduces the reliability and accuracy. In this work, a double-carrier platform was constructed on a probable excitonic insulator Ta2Pd3Te5, and the four-parameter fitting based on the double-carrier model was simplified to a single-parameter fitting by employing methods such as analyzing the shape of the Hall resistance curve and generating gate-induced Shubnikov-de Haas oscillations. Thus, we provide a reliable method for double-carrier fitting of Hall resistance and a new evidence for the existence of excitonic-insulator state in Ta2Pd3Te5.