Giant Photonic Response of Mexican-hat Topological Semiconductors for Mid-infrared to THz Applications

Abstract

The mid-infrared (MIR), far-infrared (FIR) to terahertz (THz) frequencies are the least developed parts of the electromagnetic spectrum for applications. Traditional semiconductor technologies like laser diodes and photodetectors are successful in the visible light range, but are still confronted with great challenges when extended into the MIR/FIR/THz range. In this paper, we demonstrate that topological insulators (TIs), especially those with Mexican-hat band structure (MHBS), provide a route to overcome these challenges. The optical responses of MHBS TIs can be one to two orders of magnitude larger than that of normal semiconductors at the optical-transition edge. We explore the databases of topological materials and discover a number of MHBS TIs whose bandgaps lie between $0.05\sim 0.5\mathrm{eV}$ and possess giant gains (absorption coefficients) on the order of $10^4\sim 10^5\mathrm{c}{\mathrm{m}}^{-1}$ at the transition edge. These findings may significantly boost potential MIR/FIR/THz applications such as photon sources, detectors, ultrafast electro-optical devices, and quantum information technologies.

16 pages, 3 figures

References in corpus (10)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Quantum Computing
• Topological Crystalline Insulators
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Classification of stable three-dimensional Dirac semimetals with nontrivial topology
• Unexpected mass acquisition of Dirac fermions at the quantum phase transition of a topological insulator
• Tuning phase transition between quantum spin Hall and ordinary insulating phases
• Universal phase diagrams for the quantum spin Hall systems
• Stimulated emission of terahertz radiation by semiconductor microcavities

Cited by in corpus (8)

• Colossal switchable photocurrents in topological Janus transition metal dichalcogenides
• Two-dimensional Topological Ferroelectric Metal with Giant Shift Current
• Switchable Topological Phase Transition and Novel Nonlinear Optical Properties in ReC2H Monolayer
• Abnormal Surface Nonlinear Optical Responses in Topological Materials
• THz ratchet effect in HgTe interdigitated structures
• Efficient Quantum Transduction Using Anti-Ferromagnetic Topological Insulators
• Possible Topological Superconductivity in a Topological Crystalline Insulator (Pb${}_{1-x}$Sn${}_x$)${}_{1-y}$In${}_y$Te
• Strong Long-Wave Infrared Optical Response in a Topological Semiconductor with a Mexican Hat Band Structure