Magnetic Skyrmions in Chiral Multilayers (Prof. Christopher Marrows)
In this project we will study magnetic skyrmions, nanoscale swirls of spins that possess a special topology. They appear in properly designed magnetic multilayers at room temperature and are candidates for next-generation data storage technology. It is now over a decade since the carbon footprint of the internet grew larger than that of commercial air travel, much of this energy is used to physically spin hard disks, write data to them, and write and refresh volatile memory. To drive skyrmions along a crystal using spin torque requires several orders of magnitude less current density then driving magnetic domains under ideal conditions, but this is not seen in practice in these systems so far. Magnetic skyrmions offer the prospect of vastly reducing the energy needed to write and store digital data if their properties can be controlled.
In Leeds we have a rich programme of research on skyrmions carried out with several leading European laboratories in France, Germany and Switzerland. Potential topics for PhD study include studying the thermal stability of skyrmions in order to establish their reliability as a store of digital data (arXiv:1706.01065 [cond-mat.mes-hall]), studying their transport properties as a means of electrically detecting them (arXiv:1706.06024 [physics.app-ph]), and the mobility of skyrmions at room temperature under the influence of the torques exerted by spin-polarised currents.
Two fully funded studentships (including stipend, home/EU tuition fees, and research support) are available for a 2018 start for this project. The first is partly supported by the Diamond Light Source synchrotron in Oxfordshire, and will entail close collaboration with the team of Dr Paul Steadman at the I10 beamline BLADE, including extended visits to work at the synchrotron. Further details are here. The second is supported by EURAMET, the European Association of National Metrology Institutes, and involves collaboration with the National Physical Laboratory as well as partner metrology laboratories and universities in Germany and Italy.