Yuqing is a PhD student from KTH studying quantum materials such as 2 dimensional (2D) materials.
There, the “2D” includes not only thin films, but also quasi low-dimensional materials which are bulk material by themselves but are treated as 2D, considering their low coupling between the natural plane in nuclear structures. For example, the van der Waals magnet. For the thin films, she uses pulsed laser deposition (PLD) to synthesize oxide thin films. For other low dimensional materials, she uses scattering techniques such as X-ray diffraction and neutron diffraction to characterize the nuclear and magnetic structures. Here, neutron diffraction plays an irreplaceable role in this series of study, as the ½ spin of neutrons interact with the electron when they pass by the atoms in their journey before reaching the detector, thus delivering us the microscopic information of the magnetism, especially the local interaction natures. Apart from scattering, she also makes use of Muon spin rotation and relaxation (MuSR) to learn the local field and dynamics as MuSR and neutron diffraction are good combinations in the time window of the dynamics.
Her project involves Skyrmions in chiral magnets which can help understanding of these topological textures, thus helping spintronic devices such as racetrack memories as well as the physics themselves. Moreover, involving high pressure in the van der Waals magnet helps people understand the microscopic magnetism by driving some of the coupling to the extremes where one can magnify and investigate the interplay between each other.
She thinks exploring interactions between the spins and revealing their properties are the most fun part. Especially, combining different techniques allows her to understand the topics from all different aspects comprehensively. However, there are also challenging parts. One of them is applying high pressures on the crystals. Like humans, crystals might deform and break under pressure. Sometimes the air-sensitivity will make the story even more different.
To be a student in neutron scattering is very lucky as a student studying magnetism and quantum materials since neutron diffraction provides an important approach to the spin degrees of freedom. Furthermore, courses provided by SwedNess have offered invaluable support, directly addressing students' needs.