Overcoming thermal noise in non-volatile spin wave logic

Spin waves are propagating disturbances in magnetically ordered materials. To compete as a promising candidate for beyond-CMOS application, the all-magnon based computing system must undergo the essential steps of careful selection of materials and demonstrate robustness with respect to thermal noise/variability. Here, we identify suitable materials and investigate two viable options for translating the theoretical idea of phase-dependent switching of the spin wave detector to a practical realization of a thermally reliable magnonic device by - (a) using the built-in strain in the ME cell, arising from the lattice mismatch and/or thermal expansion coefficient mismatch between the film and the substrate, for compensation of the demagnetization, and (b) using an exchange-spring structure that exhibits a strong exchange-coupling between the ME cell and PMA SWB and provides a modification of the energy landscape of the ME cell magnet. A high switching success and error-free logic functionality can be ensured if the amplitude of the detected spin wave ($<\theta>$) remains higher than a threshold value of around 6$^o$ and the detected phase falls within the window from 280$^o$ through 0 to 20$^o$ or from 100$^o$ to 200$^o$ with a maximum allowable $\phi$ range of around 100$^o$.