Millimeter-Scale, Atomically Controlled 2D Topological Insulators Revealed by Multimodal Spectroscopy
7 affiliations
- 1Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- 2Department of Physics, Gachon University, Seongnam 13120, South Korea
- 3Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
- 4Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- 5Department of Materials Science and Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- 6Department of Physics, University of Florida, Gainesville, Florida 32611, United States
- 7Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
Abstract
Quantum spin Hall insulators, also known as 2D topological insulators, are crucial 2D systems hosting topologically protected edge states. The working temperature of this topological quantum phase is dictated by the inverted bandgap. However, the previously identified large-gap 2D topological insulators are either extremely chemically unstable or cannot be made with atomistic precision over macroscopic scales. Here, we establish two-quintuple-layer Bi2Te3 and MnBi2Te4/Bi2Te3 heterostructures as atomically controlled, millimeter-scale 2D topological insulators, enabled by precision layer-by-layer growth that yields a carpet-like morphology extending coherently over macroscopic distances. This carpet-like growth mode renders the films amenable to mechanical exfoliation and subsequent wet or dry transfer. Multimodal spectroscopies and microscopies reveal the integer-layer-tuned electronic structure of (Bi2Te3)n in excellent agreement with theory. Photon-energy-dependent photoemission and time-resolved photoemission identify band inversion and band dynamics, respectively, while scanning tunneling spectroscopy resolves topological edge states that are characteristic of the 2D topological insulator phase. Thickness- and photon-energy-dependent photoemission further validate MnBi2Te4/Bi2Te3 as a robust 2D topological insulator. The large inverted gaps of ∼100 meV in (Bi2Te3)2 and ∼150 meV in MnBi2Te4/Bi2Te3 suggest operation near ambient temperature. These results define a scalable materials platform for next-generation, low-loss quantum and energy-efficient devices.
Related
- Charge-conserving creation and annihilation of topological phase singularities in atomically thin semiconductors
- Time-Resolved Fourier-Transform Millimeter-wave Spectroscopy of the simplest Criegee Intermediate, CH₂OO, in its ν₇ = 1 state
- Sub-cycle doublon-holon dynamics in one-dimensional Mott insulators revealed by two-color high-harmonic spectroscopy
- Nonlinearity-Induced Suppression of Dissipation in Bath-Coupled Floquet Topological Insulators
- Topological Boundary States and the Edge Chain in Semi-Infinite Two-Dimensional Insulators
BibTeX
@article{lee2026millimeterscale,
title = {{Millimeter-Scale, Atomically Controlled 2D Topological Insulators Revealed by Multimodal Spectroscopy}},
author = {Woojoo Lee and Qiang Gao and Yufei Zhao and Hui Li and Albert Tsui and Yichao Zhang and Yunhe Bai and Haoran Lin and Khanh Duy Nguyen and Gabriele Berruto and Gangbin Yan and Jianchen Dang and Tongyao Wu and Hossein Rokni and Thomas S. Marchese and Ying Shirley Meng and Chao-Xing Liu and Xiao-Xiao Zhang and Chong Liu and Pinshane Y. Huang and Mark C. Hersam and Binghai Yan and Shuolong Yang},
journal = {ACS Nano},
year = {2026},
month = oct,
doi = {10.1021/acsnano.6c10210},
url = {https://doi.org/10.1021/acsnano.6c10210},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Millimeter-Scale, Atomically Controlled 2D Topological Insulators Revealed by Multimodal Spectroscopy
AU - Woojoo Lee
AU - Qiang Gao
AU - Yufei Zhao
AU - Hui Li
AU - Albert Tsui
AU - Yichao Zhang
AU - Yunhe Bai
AU - Haoran Lin
AU - Khanh Duy Nguyen
AU - Gabriele Berruto
AU - Gangbin Yan
AU - Jianchen Dang
AU - Tongyao Wu
AU - Hossein Rokni
AU - Thomas S. Marchese
AU - Ying Shirley Meng
AU - Chao-Xing Liu
AU - Xiao-Xiao Zhang
AU - Chong Liu
AU - Pinshane Y. Huang
AU - Mark C. Hersam
AU - Binghai Yan
AU - Shuolong Yang
PY - 2026
DA - 2026/10/09
JO - ACS Nano
DO - 10.1021/acsnano.6c10210
UR - https://doi.org/10.1021/acsnano.6c10210
AB - Quantum spin Hall insulators, also known as 2D topological insulators, are crucial 2D systems hosting topologically protected edge states. The working temperature of this topological quantum phase is dictated by the inverted bandgap. However, the previously identified large-gap 2D topological insulators are either extremely chemically unstable or cannot be made with atomistic precision over macroscopic scales. Here, we establish two-quintuple-layer Bi2Te3 and MnBi2Te4/Bi2Te3 heterostructures as atomically controlled, millimeter-scale 2D topological insulators, enabled by precision layer-by-layer growth that yields a carpet-like morphology extending coherently over macroscopic distances. This carpet-like growth mode renders the films amenable to mechanical exfoliation and subsequent wet or dry transfer. Multimodal spectroscopies and microscopies reveal the integer-layer-tuned electronic structure of (Bi2Te3)n in excellent agreement with theory. Photon-energy-dependent photoemission and time-resolved photoemission identify band inversion and band dynamics, respectively, while scanning tunneling spectroscopy resolves topological edge states that are characteristic of the 2D topological insulator phase. Thickness- and photon-energy-dependent photoemission further validate MnBi2Te4/Bi2Te3 as a robust 2D topological insulator. The large inverted gaps of ∼100 meV in (Bi2Te3)2 and ∼150 meV in MnBi2Te4/Bi2Te3 suggest operation near ambient temperature. These results define a scalable materials platform for next-generation, low-loss quantum and energy-efficient devices.
SN - 1936-0851
SN - 1936-086X
ER -