Dr Thomas Hicken - PhD Student

University of Durham

Dr Thomas Hicken joined the Skyrmion Project as a PhD student in October 2017.

They worked under the supervision of Professor Tom Lancaster at Durham University using muon-spin spectoscopy to investigate materials hosting topological magnetic states, including skyrmions.

During the PhD we found that muon-spin spectrscopy is an excellent probe of the skyrmion state, being sensitive to dynamics in the MHz range that are inaccessible by other techniques. This led to the discovery that the skyrmion has significantly more dynamics on the MHz timescale than other magnetic phases in these materials. Through study of this response, we were able to show that in multiple system disorder induced by chemical substituion helps stabilise the skyrmion phase [1]. We also made advances in understanding the nature of both the skyrmion-hosting materials under pressure [2], and of other magnetic states such as solitons [3].

Thomas graduated with a PhD in 2021. They are currently a postdoctoral research associate at Royal Holloway, University of London, where they are studying the effect of chemical substitution on magnetically frustrated systems.

[1] T. J. Hicken et al. “Magnetism and Neel skyrmion dynamics in GaV4S8-ySey”. Physical Review Research 2, 032001(R) (2020).

[2] T. J. Hicken et al. “Megahertz dynamics in skyrmion systems probed with muon-spin relaxation”. Physical Review B 103, 024428 (2021).

[3] T. J. Hicken et al. “Energy-gap driven low-temperature magnetic and transport properties in Cr1/3MS2 (M = Nb, Ta)”. Physical Review B 105, L060407, (2022).