In-plane and interlayer magnetoresistance in FeSe

TL;DR

This study measures in-plane and interlayer magnetoresistance in FeSe, revealing temperature-dependent behaviors and field-direction effects, and suggests large interlayer transfer energy and coherence effects in the material.

Contribution

It provides detailed magnetoresistance measurements in FeSe, highlighting the role of magnetic field orientation and temperature, and introduces analysis of interlayer coherence effects.

Findings

In-plane magnetoresistance is positive below structural transition temperature.

Interlayer magnetoresistance changes sign around 18 K.

Large interlayer transfer energy inferred from coherence peak width.

Abstract

We report measurements of the in-plane and interlayer magnetoresistances of FeSe. The in-plane magnetoresistance $\Delta \rho_{ab}/\rho_{ab}(0)$ for $B \parallel c$ is positive below $T_s$ and increases with decreasing temperature, exceeding 2.5 at $T$ = 10 K and $B$ = 14 T. The field-direction dependence indicates that the in-plane magnetoresistance is basically determined by the $c$-axis component of the magnetic field. The interlayer magnetoresistance $\Delta \rho_{c}/\rho_{c}(0)$ is negative below $T_s$ but turns positive below $\sim$18 K, which is probably due to the contamination by the large in-plane magnetoresistance. The field-direction dependence of the interlayer magnetoresistance can approximately be described by a standard formula for quasi-two-dimensional electron systems except near $B \parallel ab$. The experimental magnetoresistance near $B \parallel ab$ is larger than the formula, which can be attributed to the so-called interlayer coherence peak. The large width of the peak indicates the correspondingly large interlayer transfer energy.