Emergent quantum phenomena
Our research interest
Our research revolves around the quantum phenomena emerging from the interplay of charge, spin and orbital degrees of freedom of electron in crystalline systems. Such delicate interactions, happening at a microscopic level, can give rise to collective phases of matter with unusual properties. Some highlights include topological phase transition, unconventional superconductivity, non-trivial magnetic orders and spin-textures, integer and fractional quantum Hall effect, and quasiparticle interferences, all of great relevance for future energy and information technologies. Using bespoke computational methods, we explore ways in which a material can be tuned to exhibit such quantum phases. Below are some related topics on which our research is focused.
Topological materials
Solid-state, particle, and mathematical physics are often regarded as distinct disciplines within modern physics. However, over the past few decades, a series of profound conceptual developments spanning these fields has led to the emergence of a new paradigm in condensed matter physics: the theory of topological phases of matter. Materials exhibiting such phases-referred to as topological materials (TMs)-have significantly deepened our understanding of quantum systems. In contrast to conventional classifications of materials as metals (e.g., copper) or insulators (e.g., rubber), topological materials are characterised by topological invariants, mathematical constructs that remain unchanged under continuous deformations of the system. Topology, in this context, describes global features of a material's electronic structure that are immune to local perturbations. A defining property of topological materials is the presence of robust conducting states at their boundaries (such as edges or surfaces), even when the bulk remains insulating. These boundary states are protected against scattering from impurities, thermal fluctuations, and structural imperfections, enabling dissipationless transport. Such robustness positions topological materials as promising platforms for transformative technologies in low-power electronics, spintronics, and quantum information processing. The topological materials investigated in our group fall into the following categories:
Two dimensional materials
Two dimensional (2D) materials – particularly van der Waals (vdW) materials–have become a new platform for exploring quantum anomalies in low dimensions. Composed of atomically thin layers, weakly bonded through vdW forces, they appear in different thicknesses, ranging from a single layer to bulk. We have so far discovered many exciting aspects of these materials, and are currently developing new theoretical approaches and computational techniques, employing machine learning, to predict, design and study artificial vdW superstructures with advanced functionalities. Here are some highlights:
Transition metal oxides
Metal oxides have become the building block for many applications, including sensors, catalysts, energy converters, solar cells and memory devices. Their superior chemical and physical properties enable the construction of diverse classes of superstructures and heterojunctions with unique quantum properties such as integer and fractional quantum Hall effect, unconventional superconductivity and interfacial spin textures. We study such quantum effects at the surface and interface of metal oxide heterostructures from first principles. We are particularly interested in modelling emergent quantum confinement effects at the surface and interfaces, aiming at designing artificial superstructures with advanced spintronic functionalities.
Latest research highlights
