Engineering topological surface states and giant Rashba spin splitting in BiTeI/Bi2Te3 heterostructures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Topological insulators (TIs) are materials with unique electronic properties.
• Inversion asymmetric TIs exhibit distinct characteristics compared to symmetric ones.
• Large Rashba spin-splitting (RSS) in TIs is crucial for spintronics.

Purpose of the Study:

• To investigate the potential of BiTeI/Bi2Te3 heterostructures as topological insulators.
• To explore the coexistence and tunability of topological surface states (TSS) and RSS.
• To identify new material platforms for spintronics devices.

Main Methods:

• First-principles calculations were employed.
• Analysis of Z2 invariants to confirm topological properties.
• Investigation of electronic band structure to determine RSS.

Main Results:

• The BiTeI/Bi2Te3 heterostructure is predicted to be a strong topological insulator.
• A giant Rashba spin-splitting (RSS) was observed in the heterostructure.
• Both Z2 invariants and RSS are controllable by engineering layer geometry.
• The RSS in the heterostructure can exceed that of bulk BiTeI.

Conclusions:

• The BiTeI/Bi2Te3 heterostructure is a promising candidate for topological spintronics.
• Native coexistence of TSS and RSS ensures material stability.
• Engineering heterostructure geometry offers a route to tune spintronic properties.