Quantum oscillations in the anomalous spin density wave state of FeAs

Abstract

Quantum oscillations in the binary antiferromagnetic metal FeAs are presented and compared to theoretical predictions for the electronic band structure in the anomalous spin density wave state of this material. Demonstrating a new method for growing single crystals out of Bi flux, we utilize the highest quality FeAs to perform torque magnetometry experiments up to 35 T, using rotations of field angle in two planes to provide evidence for one electron and one hole band in the magnetically ordered state. The resulting picture agrees with previous experimental evidence for multiple carriers at low temperatures, but the exact Fermi surface shape differs from predictions, suggesting that correlations play a role in deviation from ab initio theory and cause up to a four-fold enhancement in the effective carrier mass.

Magnetic anisotropy in uranium monosulfide probed by magnetic torque measurements

“…In general, the magnetic torque measurements performed on single crystals are considered as a sensitive probe for studying the magnetic, especially anisotropic properties of solids. This technique has been successfully used to study anisotropic behaviors of superconductors, heavy fermions, and various antiferromagnetic, ferromagnetic, and paramagnetic materials [31][32][33][34][35][36]. Here, we report detailed measurements of the magnetic torque of US single crystals.…”

Topologically-Driven Linear Magnetoresistance in Helimagnetic FeP

“…is nearly 300 times the zero field resistivity. This increase is more than two orders of magnitude larger than that of in FeAs in high field [8]. Given the close structural and magnetic parallels between the two materials, the only explanation is that the substitution of P for As and related significant decrease in residual resistivity produce a bigger in-field response.…”

“…This could also be an example of changing weight of multiple MR contributions with different pressure dependences. Linear MR has been seen in the other two magnetic B31 compounds in certain field ranges: FeAs shows a quadratic-linear crossover around 10 T [8], while MnP can have quasilinear MR from below 2 T [4]. However, interpretation of the latter data is complicated by the presence of metamagnetic transitions, which may alter the relation between the semi-Dirac point and magnetic order.…”

“…1) and magnetic susceptibility [3] of FeP are very similar to that of FeAs [22], with an s-shaped curvature and distinct kink at T N (which is 70 K in the arsenide), suggesting that itinerant spin-density wave magnetism is very similar in both compounds. However, even compared to the highest quality crystals of FeAs [8], the residual resistivity of FeP is extremely small (as low as 0.2 µΩ cm), with a residual resistivity ratio (RRR = ρ 300 K /ρ 1.8 K ) of up to 1500, much larger than that of CrP and CrAs [16,23,24], and rivaled only by MnP [25]. (The trend of higher RRR in phosphides appears generic to this family, as it is also observed in CoAs [26] and CoP [SI, Fig.…”

“…The orthorhombic "MnP-type" (or B31) family of materials has been under study for several decades [1][2][3][4] but has recently received much attention due to a diverse range of properties. Aside from a peripheral connection to iron-based high-temperature superconductivity [5], novel magnetism [6][7][8], quantum criticality [9,10], metal-insulator transitions [11], and indications of nontrivial electronic topology [12][13][14] have all been reported in a series of binary transition metal-pnictides. Two members of the B31 family, CrAs and MnP itself, have also been shown to superconduct upon suppression of helimagnetic order under applied pressure [9,[15][16][17], suggesting a novel interplay of ground states.…”