Basic Chemistry & Physics

Low Dimensional Systems: Order and Disorder on the Quantum Scale

PhD: Frank Elson, KTH Royal Institute of Technology (2025)

This project explored emergent quantum phenomena in low-dimensional materials, where reduced dimensionality gives rise to unique interactions between superconductivity, magnetism, and charge order. Using a combination of neutron scattering, muon spin rotation (µSR), and X-ray scattering, the research investigated materials including transition-metal dichalcogenides and low-dimensional magnetic systems.

In the superconducting compounds 1T-TiSe and 2H-TaS, the studies identified a multi-gap superconducting state and unconventional charge density wave behavior, including the first observation of a Kohn anomaly in 2H-TaS₂. In the magnetic systems CuF(DO)(pyz) and (CHNH)CuBr, neutron and muon experiments revealed field-induced magnetic excitations and a pressure-driven transition from antiferromagnetic to ferromagnetic order.

By connecting experimental results with theoretical modelling, this work provided new insight into quantum phase transitions and collective excitations in correlated electron systems, advancing the understanding of how dimensionality and symmetry govern the behavior of materials at the quantum scale.

Frank Elson completed his Master’s degree in Physics at Royal Holloway, University of London in 2021. His master’s project focused on Monte Carlo simulations of the Ising model, providing a strong foundation in computational methods and fundamental concepts in magnetism.