Ultrafast optical Antiferromagnetic Topological Spintronics

Antiferromagnetic spintronics exploits the antiferromagnetic (AFM) staggered magnetization-Néel vector to manipulate spin dependent transport properties in structures containing antiferromagnetic components.

In ATOPS, I plan to use sub 15 fs light pulses to facilitate Neel vector reorientation via optically induced Neel spin orbit torque in the room temperature Dirac Nodal line AFM material MnPd2.

The Neel vector reorientation in this material is also associated with changes in Fermi surface topology, where the orientation of the Neel vector controls switching between the degenerate and gapped Dirac states.

MnPd2 with its favourable symmetry to support Néel spin orbit torque and the presence of Dirac Nodal lines in a broad range of energies across the Fermi level makes it an ideal candidate for topological AFM spintronics applications.

I will employ optical methods that are interesting in the sense that they can control the magnetization dynamics in ultrashort time scales with high spatial resolution.

I will use magneto optical (MO) effects that are quadratic in magnetization and magneto-optical Voigt effect (MOVE) has been proposed to be an effective method to identify the Neel vector reorientation in the system. Pump probe technique will be used to measure the MOVE signal in the fully compensated AFM - MnPd2 .

ATOPS will also utilise magnetotransport techniques to characterise the material and verify the magnetic ordering.

ATOPS plans to establish experimentally that the AFM Dirac material MnPd2 is an ideal system to realise strong response of magneto-transport and optical properties to the magnetization dynamics near room temperature.