High Throughput Screening for Spin-Polarized Current in Noncollinear Magnetic Materials
- Principal Investigators:
- Prof. Hongbin Zhang
- Project Manager:
- Harish Kumar Singh
- HPC Platform used:
- NHR4CES@TUDa: Lichtenberg Cluster Darmstadt
- Project ID:
- Date published:
- The spin-dependent transport phenomena in magnetic materials can provide spin-polarized charge current and large pure spin current, which could be achieved premised on two fundamental properties, i.e., anomalous Hall conductivity (AHC) and spin Hall conductivity . The AHC is characterized as a generation of transverse voltage drop or current density (depending on the boundary conditions) originating from the longitudinal electric currents. The existence of ﬁnite AHC in noncollinear antiferromagnets has attracted noticeable attention due to possible applications in antiferromagnetic spintronics for information storage and data processing , where the kagome lattice turns out to be an intriguing prototypical lattice to host giant AHC with noncollinear magnetic configuration . In this work, we proposed and studied antiperovskites (APVs) as a new class of magnetic materials exhibiting significant AHC in frustrated antiferromagnetic states .
DFT calculations are performed using the projector augmented wave method as effectuated in the VASP package . The AHC is evaluated using the WannierTools code , with the maximally localized Wannier functions (MLWFs)  constructed automatically based on an in-house developed algorithm .
In this work, we carried out a systematic analysis of 54 cubic APV systems (space group Pm3m) with the chemical formula M3XZ to determine their magnetic ground states and transport properties . As shown in Fig. 1, Γ4g and Γ5g are the two most common noncollinear magnetic conﬁgurations reported for APVs, with the 120° magnetic angle conﬁgurations lying in the (111)-plane. The Γ4g state can be obtained from Γ5g by simultaneously rotating the moments of three M-atoms within the (111)-plane by 90°. Explicit calculations were performed to obtain the energies of eight possible magnetic configurations, with four of them shown in Fig. 1, i.e., Γ4g, Γ5g, non-magnetic (NM), ferromagnetic (FM). It is observed that fourteen APVs end up with noncollinear ground state, including newly-predicted Cr3XN (X = Ir and Pt) with the Γ4g magnetic ground state. Large AHC is observed for the APVs with the Γ4g ground state, such as the AHC of Cr3IrN and Cr3PtN are 414.6 and 278.6 S/cm, respectively. More interestingly, detailed analysis reveals that AHC and the concomitant anomalous Nernst conductivity (ANC) can get significantly enhanced when topologically protected Weyl nodes are shifted towards the Fermi energy, which can be achieved by applying epitaxial strain as demonstrated for Mn3PdN. Nevertheless, we found that such Weyl nodes are not something unique only for those systems with a noncollinear magnetic ground state, but also for all the magnetic materials with ferromagnetic ground states [10, 11].
This work is published in the npj Computational Materials journal .
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- Institute / Institutes:
- Materials Science
- Technische Universität Darmstadt