Bernhard Pruckner Dipl.-Ing. Publications

Biography Bernhard Pruckner was born in 1994 in Vienna. He received his BSc degree in Technical Physics at the TU Wien in 2017. After completing his BSc degree, Bernhard was offered an exchange internship at Instituto Superior Tecnico in Lisbon where he was modeling laser-plasma interactions using a finite difference method. He continued his study at the TU Wien simultaneously working on his Master thesis at the Austrian Institute of Technology on coupled finite volume - finite element approach for simulating solidification processes in aluminum alloys. He successfully defended the thesis at the TU Wien in 2020 and received his Masters degree in Technical Physics. After working at the Division of Nuclear Medicine at AKH Wien he joined the Institute for Microeletronics in December 2022, where he is pursuing a PhD degree in micromagnetic simulations for non-volatile magnetic memory devices.

Noncollinear antiferromagnets (nc-AFMs) like Mn₃Sn have emerged as promising candidates for spin-polarizing layers in next-generation spin orbit torque magnetoresistive memory RAM (SOT-MRAM) devices. Mn₃Sn exhibits the magnetic spin Hall effect (MSHE), which leads to the generation of out-of-plane polarized spin currents from an in-plane charge current. The integration of Mn₃Sn into SOT-MRAM cells, facilitates field-free perpendicular magnetization switching, eliminating the need for an externally applied magnetic field.

In addition, Mn₃Sn can potentially be used as a magnetic memory layer, due to its spin structure, where the Mn atoms, carrying the 3 magnetic sub-moments, are arranged in a two-dimensional Kagome lattice. Tensile strain breaks the crystal symmetry, introducing a small net magnetic moment m_net. High strain leads to two distinct energy minima, corresponding to a stable 'up' and 'down' state of m_net. Applying an external magnetic field shifts the energy barriers, facilitating deterministic switching.

The MSHE can be fully electrically controlled by switching the magnetic orientation of Mn₃Sn in a Mn₃Sn/Mo/CoFeB trilayer structure (Fig 1a). Applying a charge current I_MSHE in x-direction leads to the switching of m_FM of the CoFeB layer by the MSHE. Further applying I_AFM > I_MSHE to the structure leads to, in turn, the switching of m_net by spin-polarized current leaking from the CoFeB layer into the Mn₃Sn layer. The Oersted field generated by a charge current in the Mo layer, is sufficient to enable deterministic switching of the Mn₃Sn layer by shifting the energy barriers (Fig 1b). This scheme shows the pathway to additional control over MSHE-induced switching in future SOT-MRAM.