Topological and Chiral Matter – Physics and Applications

This Special Topic issue will highlight recent developments in the experimental and theoretical physics of topological and chiral materials, emphasizing their possible practical applications. Topology – a mathematical concept – has recently gained attention as an interdisciplinary topic encompassing condensed matter physics, solid-state chemistry, materials science, and electrical and mechanical engineering. The materials of interest include topological insulators, Dirac and Weyl semimetals, topological metals, and superconductors. It is theoretically predicted that more than half of all materials are categorized as topological. By analogy with the spin and electronic systems, topological concepts have been extended into phonons, resulting in the birth of topological phononics. It has been recognized that topological materials have direct connections with complex materials in biology where the unique mechanical, optical, and transport properties are utilized by living organisms. Topological chiral materials are another fascinating class of materials that exhibit both topological order and chirality. Chirality refers to the property of an object that cannot be superimposed onto its mirror image. The absence of improper symmetries results in fascinating electronic properties, such as protected surface states across the Fermi surface. This Special Topic issue aims to highlight the evolution of the topological and chiral matter field to practical applications. It invites contributions, which deepen the understanding of topological and chiral materials, provide guidance for the search for new materials, and address approaches for engineering such materials for applications in electronic, photonic, spintronic, superconducting, and phononic devices.

Guest Editors: Maia G. Vergniory, Takeshi Kondo, and Nicholas A. Kotov