Electronic ground state of MnB$_{4}$

TL;DR

This study experimentally determines that MnB4 has a pseudo-gap electronic ground state without magnetic order, clarifying previous uncertainties and confirming recent theoretical predictions.

Contribution

The paper provides the first experimental evidence of MnB4's electronic ground state as a pseudo-gap system, resolving prior ambiguities and disproving magnetic order claims.

Findings

MnB4 has a pseudo-gap electronic ground state.

No magnetic order observed in MnB4.

Experimental results agree with recent band structure calculations.

Abstract

Recent studies have dealt with the electronic and magnetic ground state properties of the tetraboride material MnB$_4$. So far, however, the ground state properties could not be established unambiguously. Therefore, here we present an experimental study on single-crystalline MnB$_4$ by means of resistivity and magnetization measurements. For this, we have developed a sample holder that allows four-point ac resistivity measurements on these very small ($\sim$\,100\,$\mu$m) samples. With our data we establish that the electronic ground state of MnB$_4$ is intrinsically that of a pseudo-gap system, in agreement with recent band structure calculations. Furthermore, we demonstrate that the material does neither show magnetic order nor a behavior arising from the vicinity to a magnetically ordered state, this way disproving previous claims.