Emergent topological semimetal from quantum criticality

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Topological Phases of Matter

Background:

• Electronic topology is typically described by Bloch states and band structure.
• Electron-electron interactions in metals are usually modeled using quasiparticles.
• Quantum critical states represent unique material conditions where conventional descriptions may fail.

Purpose of the Study:

• To investigate topological phase emergence in materials without well-defined quasiparticles.
• To explore the role of quantum critical states in topological phase formation.
• To analyze the influence of magnetic field and pressure on topological phases.

Main Methods:

• Experimental study of the quantum critical compound CeRu4Sn6.
• Application of magnetic field and pressure to tune material properties.
• Theoretical modeling using a Weyl-Kondo semimetal model at a quantum critical point.

Main Results:

• A topological semimetal phase was observed to emerge from the quantum critical state.
• The topological phase exhibited a dome structure dependent on magnetic field and pressure.
• The Weyl-Kondo semimetal model showed topological crossings beyond the quasiparticle framework.

Conclusions:

• Quantum critical fluctuations and symmetry are crucial for discovering emergent topological phases.
• The findings challenge the traditional quasiparticle picture in describing topological states.
• This research opens new avenues for exploring novel topological materials.