Observation of Dirac state in half-Heusler material YPtBi

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Physics

Background:

• Half-Heusler compounds exhibit diverse electronic ground states, including superconductivity and heavy-fermion behavior.
• These materials are predicted to host non-trivial topological electronic states, making them attractive for fundamental physics and device applications.

Purpose of the Study:

• To systematically investigate the electronic properties of the superconducting half-Heusler compound YPtBi in its normal state.
• To identify and characterize topological electronic states within YPtBi using experimental techniques.

Main Methods:

• Angle-resolved photoemission spectroscopy (ARPES) was employed to study the electronic band structure.
• First-principles calculations were performed to support and interpret the experimental findings.

Main Results:

• A Dirac state was observed at the $\Gamma$ point of the Brillouin zone, 500 meV below the Fermi level.
• Multiple Fermi surface pockets, including hexagonal and half-oval shapes, were identified at the $\Gamma$ and K points.
• Rashba-split bands and multiple Fermi-level-crossing surface states were detected.

Conclusions:

• The experimental observation of a Dirac state in YPtBi confirms its potential for hosting topological electronic phases.
• This study establishes YPtBi and related half-Heusler compounds as a significant platform for exploring novel topological phenomena and future electronic devices.