Extremely large magnetoresistance induced by Zeeman effect-driven electron-hole compensation and topological protection in MoSi2

Abstract

The magnetoresistance is the magnetic field induced change of electrical resistivity of a material. Recent studies have revealed extremely large magnetoresistance in several nonmagnetic semimetals, which has been explained on the basis of either electron-hole compensation or the Fermi surface topology, or the combination of both. Here, we present a single crystal study on MoSi2, which exhibits extremely large magnetoresistance, approaching almost 10 7 % at 2 K and 14 T magnetic field. It is found that the electron-hole compensation level in MoSi2 evolves with magnetic field, which is resulted from strong Zeeman effect, and found beneficial in boosting the large non-saturating magnetoresistance. The non-trivial Berry phase in the de Haas-van Alphen oscillations and the moderate suppression of backward scattering of the charge carriers lend support for the topological nature of this semimetal. The ultra-large carrier mobility of the topologically protected charge carriers reinforces the magnetoresistance of MoSi2 to an unprecedented large value.

Strong correlation between mobility and magnetoresistance in Weyl and Dirac semimetals

“…It is essential to examine the variability in MR with respect to the mobility in these compounds. We gathered these two quantities for various compounds at ∼2 K and 9 T from literature [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][39][40][41][42]. As MR varies with the field, it is more valid to consider the slope of the MR with the field than considering the value of MR in a fix field.…”

“…Depending on their degeneracy, topological semimetals are further distinguished and classified into Weyl semimetals (WSM) and Dirac semimetals. The discovery of Weyl fermions in transition metal monopnictides [1][2][3][4][5][6] has facilitated the discovery of additional Dirac and Weyl semimetals in the various families of compounds [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

Antiferromagnetism and large magnetoresistance in GdBi single crystal

“…The extremely large magnetoresistance (XMR) has been observed in several binary intermetallic compounds like WTe 2 , MoSi 2 , WSi 2 , NbP, MoP 2 , WP 2 etc. Ultra-high mobility (≈ 10 4 cm 2 /V s) and electron-hole resonance with relatively lesser carrier concentration are the reasons for the XMR in these compounds [10][11][12][13][14]. Although, such XMR is observed in non-magnetic intermetallic compounds, the natural extension of these studies is to combine the topological aspects with the strong electronic correlations.…”

Putting a spin on topological matter

“…The carrier density highly depends on the exact crystal parameters, such as the position of the Fermi level, which is likely the reason why the butterfly is not observed in all devices. Contributions of the Zeeman effect to an extremely large MR have previously been identified in MoSi 2 [182], WTe 2 [183,184], and Cd 2 As 3 [185]. showing that the magnetic field influences the carrier density.…”

“…Having observed a butterfly MR in some, but not all samples, provides a great opportunity to study this anomalous version of the extremely large MR. Such a large increase in resistance can be found in other materials as well and can be caused by a near perfect balance between electron and hole densities in the two-band Drude model [169,181,182]. In this model the longitudinal resistivity is given by…”