Topological valley pumping in Weyl semimetals

Area of Science:

• Condensed matter physics
• Topological materials science

Background:

• Weyl semimetals exhibit unique electronic properties due to their band structure.
• Topological pumping refers to the transport of quantized charges or properties under periodic modulation.

Purpose of the Study:

• Investigate topological pumping in Weyl semimetals driven by dual AC electric fields.
• Understand the origin and characteristics of the generated current.
• Explore potential applications in novel electronic devices.

Main Methods:

• Theoretical investigation of Weyl semimetals.
• Application of two AC electric fields along y and z directions.
• Analysis of anomalous velocity and Berry curvature effects.
• Characterization of particle and valley currents.

Main Results:

• Topological pumping is driven by anomalous velocity linked to Berry curvature.
• The pumping current direction depends on Weyl fermion chirality.
• A net valley current is generated, despite vanishing total particle current.
• The generated valley current is noiseless.

Conclusions:

• Topological pumping in Weyl semimetals offers a route to generate valley currents.
• The generated noiseless valley current has potential applications in valleytronics.
• Understanding the role of Berry curvature is key to controlling topological transport.