Topological Breakthroughs: Tuning Quantum States in 2D Heterostructures
July 23, 2024
Charge transfer at the interface between BiSe and Bi2Se3 induces giant Rashba splitting in a few layers of Bi2Se3.
Scientific Achievement
Through first principles calculations, CFN staff & collaborators engineered topological properties in 2D Bi2Se3/BiSe/transition metal dichalcogenide heterostructures through interface charge transfer, which creates Dirac surface electronic states.
Significance and Impact
This work presents a new method to control topological properties in 2D materials, with promise for designing better optimized electronic materials for quantum devices.
Research Details
Heterostructures of the topological insulator Bi2Se3 on transition metal dichalcogenides (TMDCs) offer a new materials platform for studying novel quantum states by exploiting the interplay among topological orders, charge orders, and magnetic orders. The diverse interface attributes, such as the material combination, charge rearrangement, defects, and strain, can be utilized to manipulate the quantum properties of this class of materials. Recent experiments with Bi2Se3/NbSe2 heterostructures show signatures of strong Rashba band splitting due to the presence of a BiSe buffer layer, but the atomic level mechanism is not fully understood. We conduct first-principles studies of the Bi2Se3/BiSe/TMDC heterostructures with five different TMDC substrates (1T phase VSe2, MoSe2, and TiSe2 and 2H phase NbSe2 and MoSe2). We find significant charge transfer at both BiSe/TMDC and Bi2Se3/BiSe interfaces driven by the work function difference, which stabilizes the BiSe layer as an electron donor. The electric field of the Bi2Se3/BiSe interface dipole breaks the inversion symmetry in the Bi2Se3 layer, leading to the giant Rashba band splitting in two quintuple layers and the recovery of the Dirac point in three quintuple layers, with the latter otherwise occurring only in thicker samples with at least six Bi2Se3 quintuple layers. In addition, we find that strain can significantly affect the charge transfer at the interfaces. Our study presents a promising avenue for tuning topological properties in heterostructures of two-dimensional materials, with potential applications in quantum devices.
- The interface dipole field in the 2D heterostructure breaks inversion symmetry, leading to a giant Rashba band splitting and reemergence of Dirac surface states in thin Bi2Se3
- The study further highlights the role of strain on charge transfer and topological properties.
Publication Reference
Jiang, Xuance, Turgut Yilmaz, Elio Vescovo, and Deyu Lu. "Manipulating topological properties in Bi 2 Se 3/BiSe/transition metal dichalcogenide heterostructures with interface charge transfer." Physical Review B 109, 115112 (2024).
DOI: https://doi.org/10.1103/PhysRevB.109.115112
OSTI: www.osti.gov/biblio/2338135
Acknowledgment of Support
We thank Dr. C.-Z. Chang for providing the ARPES data used in this study. We thank Dr. J. Cano for the valuable discussions. This research used the Theory and Computation resources from the Center for Functional Nanomaterials (CFN) and resources of the National Synchrotron Light Source II, which are U.S. Department of Energy Office of Science User Facilities, operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704.
2024-22059 | INT/EXT | Newsroom