Topological Materials for Functional Optoelectronic Devices

Abstract

The recent realization of topology as a mathematical concept in condensed matter systems has shattered Landau's widely accepted classification of phases by spontaneous symmetry breaking as he famously said, "a particular symmetry property exists or does not exist." Topological materials (TMs) such as topological insulators and topological semimetals, are characterized by properties that depend on the topology of the band structure. Such dependence has drastic implications on the optical, electrical, and thermal properties of the material. Fundamental physics of TMs is currently under active research in condensed matter, materials science, and high energy physics. In this review, recent advances in exploiting the unique properties of TMs to realize functional optoelectronic devices are surveyed. Current and future applications that are, or may be, enabled by their unique properties are discussed. Although many theoretical ideas have been proposed over the past decade or so on using TMs in optoelectronic applications, the focus will be on experimentally realized devices.

Topological Insulator Metamaterials

“…Detectors based on superconducting materials have recently established themselves as the best choice for single photon applications owing to their high sensitivity, detection efficiency, as well as fast response. Topological materials with strong photocurrent responses enhanced by metamaterials are excellent candidates for chiral light detection . A topological superconductor can potentially combine the superior features of the typical superconducting single photon detectors with the chiral sensitivity arising from the topological bands.…”

“…Topological materials with strong photocurrent responses enhanced by metamaterials are excellent candidates for chiral light detection. 218 A topological superconductor can potentially combine the superior features of the typical superconducting single photon detectors with the chiral sensitivity arising from the topological bands.…”

Strong Self‐Enhancement of Optical Nonlinearity in a Topological Insulator with Generation of Tamm State

“…As a novel quantum state of matter, topological insulators (TIs) have recently attracted broad attentions in condensed matter physics, optoelectronics, and photonics due to the fantastic electronic and optical behaviors. [15,16] Different from the conventional materials, TIs exhibit topologically protected conducting edge/surface states surrounding the insulating bulk. [17] The time-reversal symmetry in the edge/surface states contributes to the avoidance of electron backscattering from impurities/defects without magnetism.…”

“…[ 16 ] For example, the nonlinear refractive index of Sb 2 Te 3 TI can reach the level of 10 −9 m 2 W −1 , which is 2 orders of magnitude larger than those of graphene and TMD atomic layers. [ 22 ] Besides ultrahigh nonlinear refractive indices, 3D TIs possess some other advantages, containing ultrabroad operating frequency ranges, [ 15 ] flexible fabrication of micro‐ and nano‐scale structures, [ 23 ] and support of surface plasmons from ultraviolet to terahertz, [ 16 ] and compatibility with conventional manufacturing processes. [ 24 ] 3D TIs will inject enormous vitality into nonlinear optics, especially micro‐ and nano‐scale nonlinear frequency conversion.…”

Engineering supramolecular helical assemblies via interplay between carbon(sp) tetrel and halogen bonding interactions

“…Therefore, they inspired the synthesis of a plethora of artificial systems, which exhibit attractive functions for various applications including asymmetric catalysts, optoelectronic materials, and biomolecular and chiral recognition. [1][2][3][4][5][6][7][8][9] Thus, over the past several decades, chemists have been motivated to develop strategies to form helical conformations, one of which involves the formation of a supramolecular helix by the self-assembly of monomers, which requires an in-depth understanding of noncovalent interactions. [10][11][12] Among these interactions, while hydrogen bonding and pÁ Á Áp stacking interactions remain to be a major interaction, 13 it has been increasingly recognized that other noncovalent interactions such as halogen, chalcogen, pnictogen and tetrel bonding can also be exploited to obtain desired aggregate structures.…”