Gautam Gurung

My current research interest is exploring the properties of two-dimensional (2D) AFM materials for their relevant use in AFM spintronics. Antiferromagnets are robust against external perturbations, produces zero stray fields and exhibits ultrafast dynamics. They are promising functional material for spintronic applications. 2D materials can reduce the size of such devices and enhance the functionality by the associated unique properties. They also have further degrees of freedom which can be exploited easily to achieve desired symmetry for relevant spintronic properties.

My research is focused on computational materials science for exploring the properties of ferromagnetic and antiferromagnetic (AFM) materials (with collinear or noncollinear magnetic moment arrangement) relevant to spintronics. AFM materials can be used as the principal component to design ultrafast, robust and dense spintronic devices in AFM spintronics.  Using symmetry analyses, first principles methods based on density functional theory, tight binding Hamiltonian models and magnetization dynamics techniques, we predicted that noncollinear antiferromagnetic antiperovskites can be used as a functional element in spintronic devices as an information carrier, a spin-torque generator, and a spin source [1 - 4].

Fig. Symmetry analysis in different noncollinear antiferromagnet exhibiting mirror (M) and magnetic mirror (Time reversal + mirror) symmetry. Spin texture on the fermi surface in the first Brillouin zone corresponding to mirror symmetry.

Experimental findings of the stable 2D magnetic materials have opened exciting platform to explore their use in spintronic devices. We are interested in understanding the possible use of the multilayer of 2D magnetic materials to exploit the feasibility of exploiting their degrees of freedom to turn on different transport properties like anomalous Hall conductivity (AHC), magnetic tunnel junctions, spin Hall conductivity (SHC) etc. Furthermore, we will extend our prediction of the unconventional components of the SHC in the low symmetry noncollinear AFM materials by designing different symmetry even in the case of highly symmetric materials either magnetic or nonmagnetic. We also use the first principles method to understand the use of the noncollinear AFM materials in magnetic tunnel junctions.

1. G. Gurung, D. F. Shao, and E. Y. Tsymbal, Transport spin polarization of noncollinear antiferromagnetic antiperovskites, Phys. Rev. Mat. 5, 124411 (2021).

2. G. Gurung, D. F. Shao, E. Y. Tsymbal, Spin-torque switching of noncollinear antiferromagnetic antiperovskites, Phys. Rev. B 101, 140405(R) (2020).

3. G. Gurung, D. F. Shao, T. R. Paudel, E. Y. Tsymbal, Anomalous Hall conductivity of noncollinear magnetic antiperovskites, Phys. Rev. Mat. 3, 044409 (2019).

4. T. Nan, C. X. Quintela, J. Irwin, G. Gurung, D. F. Shao, J. Gibbons, N. Campbell, K. Song, S-Y Choi, L. Guo, R. D. Johnson, P. Manuel, R. V. Chopdekar, I. Hallisteinsen, T. Tybell, P. J. Ryan, J-W. Kim, Y. Choi, P. G. Radaelli, D. C. Ralph, E. Y. Tsymbal, M. S. Rzchowski, C. B. Eom, Controlling spin current polarization through non-collinear antiferromagnetism, Nat. Commun. 11, 1 (2020).

5. D. F. Shao, G. Gurung, S. H. Zhang, E. Y. Tsymbal, Dirac nodal line metal for topological antiferromagnetic spintronics, Phys. Rev. Lett. 3, 024405 (2019).