Anisotropic giant magnetoresistance in NbSb2

TL;DR

This paper reports extremely large, non-saturating magnetoresistance and a magnetic field-induced metal-semiconductor crossover in NbSb2, linked to Fermi surface changes involving high-mobility holes and low-mobility electrons.

Contribution

It demonstrates giant magnetoresistance and field-induced electronic structure changes in NbSb2, revealing new insights into anisotropic magnetotransport phenomena.

Findings

Magnetoresistance ratio up to 4.3×10^6% at 0.4 K and 32 T

Observation of metal-semiconductor crossover induced by magnetic field

Fermi surface change involving high-mobility holes and low-mobility electrons

Abstract

The extremely large transverse magnetoreistance (the magnetoresistant ratio $\sim 1.3\times10^5\%$ in 2 K and 9 T field, and $4.3\times 10^6\%$ in 0.4 K and 32 T field, without saturation), and the metal-semiconductor crossover induced by magnetic field, are reported in NbSb$_2$ single crystal with electric current parallel to the $b$-axis. The metal-semiconductor crossover is preserved when the current is along the $ac$-plane but the magnetoresistant ratio is significantly suppressed. The sign reversal of the Hall resistivity in the field close to the crossover point, and the electronic structure calculation reveals the coexistence of a small number of holes with very high mobility and a large number of electrons with low mobility. These effects are attributed to the change of the Fermi surface induced by the magnetic field.