# Topological-insulator-based terahertz modulator

Article · Xinbo Wang, Liang Cheng, Yang Wu, Dapeng Zhu, Lan Wang, Jian‐Xin Zhu, Hyunsoo Yang, Elbert E. M. Chia

- Archive id: doi:10.1038/s41598-017-13701-9
- Published: 2017-10-12
- Venue: Scientific Reports
- DOI: https://doi.org/10.1038/s41598-017-13701-9
- PMID: 29044164
- Citations: 978
- Source URL: https://doi.org/10.1038/s41598-017-13701-9
- PDF: https://www.nature.com/articles/s41598-017-13701-9.pdf
- Provenance: openalex

## Abstract

Abstract Three dimensional topological insulators, as a new phase of quantum matters, are characterized by an insulating gap in the bulk and a metallic state on the surface. Particularly, most of the topological insulators have narrow band gaps, and hence have promising applications in the area of terahertz optoelectronics. In this work, we experimentally demonstrate an electronically-tunable terahertz intensity modulator based on Bi1:5Sb0:5Te1:8Se1:2 single crystal, one of the most insulating topological insulators. A relative frequency-independent modulation depth of ~62% over a wide frequency range from 0.3 to 1.4 THz has been achieved at room temperature, by applying a bias current of 100 mA. The modulation in the low current regime can be further enhanced at low temperature. We propose that the extraordinarily large modulation is a consequence of thermally-activated carrier absorption in the semiconducting bulk states. Our work provides a new application of topological insulators for terahertz technology.

_Abstract reproduced under CC-BY (publisher license, via OpenAlex)._

Topics: [Topological Phases & Anyons](https://space-kitty.com/topics/topological-matter)

---
Space Kitty Archive · https://space-kitty.com · API: https://space-kitty.com/api/v1 · MCP: https://space-kitty.com/mcp · Premium: $0.20/request via x402 (Base Sepolia (testnet)). Metadata: arXiv (CC0), OpenAlex (CC0), Europe PMC (CC BY/CC0 works), ClinicalTrials.gov.