Photo of  Natalie Whitehead

Natalie Whitehead

PhD Project


Graded Index Magnonics

Supervisors: Prof. Volodymyr Kruglyak, Dr. Thomas PhilbinDr. Simon Horsley


As conventional semiconductor-based technologies are rapidly approaching their fundamental limits, the search for alternatives is underway. One alternative, magnonics, explores the use of precessional excitations of ordered spins in magnetic materials – so called spin waves – as information and signal carriers within networks of magnonic waveguides. In this project, we aim to explore the use of the non-uniformity of the internal magnetic field and magnetisation inherent to magnetic structures for guiding spin waves within networks of magnonic waveguides. The non-uniformities create a medium of graded refractive index for propagating magnetostatic and dipole-exchange spin waves. The character of the non-uniformity could be tuned and potentially programmed using the applied magnetic field. These functionalities would open the possibility of a novel reconfigurable computing technology based on the principles of the graded index magnonics. The concepts of graded index photonics and transformation optics will be mapped on to spin waves, after which the most successful and promising of them will be verified first numerically, using micromagnetic simulations based on the Object Oriented Micromagnetic Framework (OOMMF) software, and then experimentally, using time resolved scanning Kerr microscopy.