Related Experiment Video
Updated: Jun 26, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
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Topological phase transition and tunable surface states in YBi
Ramesh Kumar1, Mukhtiyar Singh1
1Department of Applied Physics, Delhi Technological University, New Delhi 110042, India.
Summary
Yttrium monobismuthide (YBi) is a trivial semimetal at ambient pressure. Applying pressure or epitaxial strain can induce topological phase transitions, making YBi a promising material for studying the link between extremely large magnetoresistance and topology.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Non-magnetic rare-earth monopnictides exhibit extremely large magnetoresistance (XMR) and topological properties.
- Yttrium monobismuthide (YBi) shows XMR up to 10^5%, but its topological characteristics require further investigation.
Purpose of the Study:
- To investigate the structural, electronic, and topological properties of YBi using hybrid density functional theory.
- To clarify the topological nature of YBi and identify conditions for topological phase transitions.
Main Methods:
- Hybrid density functional theory calculations.
- Analysis of structural, electronic band structure, and surface band structure.
- Calculation of Z2 topological invariants using product of parities and Wannier charge centers.
Main Results:
- YBi is a topologically trivial semimetal at ambient pressure.
- Topological phase transitions from trivial to non-trivial occur at 6.5 GPa volumetric pressure and 3% epitaxial strain.
- These transitions occur below the structural phase transition pressure of YBi (24.5 GPa).
- The non-trivial state is characterized by band inversions between Y-d and Bi-p bands at Gamma and X points.
Conclusions:
- YBi can be tuned to a topological non-trivial phase via moderate pressure or epitaxial strain.
- The ability to achieve a non-trivial phase with small epitaxial strain makes YBi films ideal for exploring the relationship between XMR and topology.
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