In the last century, the electronic phases are being understood using Landau’s approach, which characterizes the states in terms of underlying symmetries that are spontaneously broken. However, over the decades, physicists are using a different classification paradigm based on the notion of topological order. In a topological phase, certain fundamental properties are insensitive to smooth changes in material parameters and can’t change unless the system passes through a quantum phase transition.
These topological phases can be realized using quantum materials which is known as Topological quantum devices. These topological quantum devices are expected to host exotic topological quasi-particles like Majorana fermion, Para-fermion, Anyons, Excitons, Neutral modes etc. Exploring these emergent quasiparticles with their topological properties is exciting in table top condensed matter experiments as well as promising because these emergent excitations may have very strong influence in shaping the future area of quantum computers, in particular for decoherence free topological quantum computing.
Therefore, the creation, detection and manipulation of topological properties using topological quantum devices are the forefront research area in condensed matter physics. These topological aspects can be explored using low-dimensional systems like graphene, transition metal dichalcogenides, topological insulators, Indium Arsenide’s nanowire with spin-orbit coupling and their interfaces with superconductors and magnetic materials. The high-quality devices can be demonstrated by implication of cutting-edge technologies like both side graphite gated hexagonal boron nitride encapsulations. In order to study the topological properties of the quantum devices, we implement cutting edge probes like tunneling spectroscopy, thermal transport, quantum noise, compressibility measurements.
Furthermore, we study the emergent superconductivity and Mott insulator behavior in the topological flatland of twisted two-dimensional systems having a phase diagram reminiscence of high-temperature superconducting families, which has motivated unprecedented research activities worldwide. It has been shown theoretically that such a flatland can be described by topological order parameter (Chern insulator) without any external magnetic field.
In summary, exploring the emerging topological properties in topological quantum devices will be the key focus area of the group, which will help to build the decoherence free quantum computers in future.