Emergent qunatum 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 three seemingly unrelated branches of modern physics. During the past decades, however, a set of brilliant ideas, cutting across these branches, has brought about a new paradigm in condensed matter physics, the topological phases of matter. Materials representing such phases, also known as topological materials (TMs), have changed our understanding of the laws of quantum theory. These materials do not obey the traditional conventions used for describing a normal metal, like copper or an insulator like a piece of rubber. Instead, they are classified by topology, a mathematical concept, used to describe those aspects of geometrical objects, which remain unchanged under continuous deformation (like the number of holes in a slice of Swiss cheese). In a solid material with a non-trivial topology, this means the boundaries (like edges or surface) can behave as a perfect channel for conducting electricity without any dissipation and immune from external perturbations such as heat, mechanical distortion and structural imperfections. As such, TM’s are believed to be capable of revolutionising future energy and quantum information technologies. The TM’s studied in our group fall into one 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
