Research

Topological Quantum Crystal

Over the past decade, topology has taken center stage in condensed matter physics and materials science. Many topological phases, such as 3D topological insulators (TI) and Weyl semimetals, have been observed. Despite tremendous progress, known topological phases have been largely confined in weakly-interacting, bulk materials under equilibrium. Our group search for topological phases in non-equilibrium states, in nanostructures and 2D materials, in broken symmetry states and in strongly correlated materials. These new topological phases will present key future directions over the next decade and expected to exhibit a wide range of fundamentally new physics such as Floquet topological phases, Majorana fermions, topological charge fractionalization, topological order and non-abelian anyons.

Topological Responses

On a more fundamental level, the topological phases arise from the geometric properties of the quantum wave function such as the quantum metric and Berry curvature. These quantum geometrical properties provide deep information about quantum states beyond the E-k dispersion, but they remain difficult to access experimentally. Therefore, related to topology, our other goal is to search, discover, and understand quantum geometrical responses of novel quantum materials. When tailored properly, the topological and geometrical responses can give rise to new, emergent functionalities, which are crucial for quantum sensing, quantum communications, and quantum computation technologies.

Topological Quantum Chemistry

Despite tremendous progress of topological quantum materials, the research has been largely confined in condensed matter physics. In order to truly utilize the nontrivial topology beyond the realm of physics, crucial challenges remain. Indeed, the physics of topological phases and Berry phase are quite abstract, which has led to a “gap” between topological theory and research in other disciplines. It is very important and urgent to bridge such a “gap” over the next decade. We can all benefit from such synergy due to following facts:

(1) It is actually much more intuitive to think about topology from the perspective of a chemist, which can sparkle new ideas and new understanding.

(2) Although recently physicists have started to realize the great potential of topological materials in areas like photovoltaics, thermoelectrics, catalysts and ferroelectrics, their proposals still remain highly theoretical and abstract. Moreover, to apply topological effects in the actual physical chemistry settings, advanced chemical and material engineering are required. 

Our group has solid background on topological physics and theory, knowledge on materials, and experience on advanced material preparations and characterizations, and we are enthusiastic to bridge such a “gap” among different disciplines in the highly synergetic and collaborative environment provided by CCB or more broadly, the Boston area.