Tunable Weyl and Dirac states in the nonsymmorphic compound CeSbTe

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Topological semimetals feature unique electronic band structures with degeneracies.
• Exotic topological phases, beyond Dirac and Weyl, are being discovered.
• Magnetic order can break time-reversal symmetry, influencing topological states.

Purpose of the Study:

• To investigate the potential of CeSbTe as a platform for realizing multiple topological semimetal states.
• To explore the influence of magnetic order on the electronic structure of CeSbTe.
• To discover new topological phases and band degeneracies in magnetic materials.

Main Methods:

• Experimental synthesis and characterization of CeSbTe.
• Tuning magnetic order with external magnetic fields.
• Magnetic group theory analysis.
• Ab initio electronic structure calculations.

Main Results:

• CeSbTe exhibits a rich variety of topological semimetal states.
• Different magnetic orders in CeSbTe are accessible via small magnetic fields.
• The material hosts the first nonsymmorphic magnetic topological phase with an eightfold band crossing.
• Antiferromagnetic order expands space groups allowing high-order band degeneracies.

Conclusions:

• CeSbTe is a versatile platform for studying magnetism-topology interplay.
• The compound allows tuning through multiple topologically distinct phases.
• Discovery of new topological phases and band degeneracies is facilitated by magnetic order.