Room-temperature chiral charge pumping in Dirac semimetals

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Chiral anomaly, a topological effect in Weyl semimetals, is theoretically predicted but experimentally challenging to observe.
• Existing experimental signatures, like negative longitudinal magnetoresistance, are typically limited to low temperatures.

Purpose of the Study:

• To investigate field-modulated chiral charge pumping and valley diffusion in Cd₃As₂.
• To explore novel experimental signatures of the chiral anomaly beyond conventional methods.
• To demonstrate room-temperature manipulation of valley polarization in topological semimetals.

Main Methods:

• Utilizing Cd₃As₂ as a model Weyl semimetal.
• Measuring nonlocal responses and negative field dependence.
• Detecting magneto-optic Kerr effect under parallel electric and magnetic fields.

Main Results:

• Observed field-modulated chiral charge pumping and valley diffusion in Cd₃As₂.
• Identified unusual nonlocal responses with negative field dependence up to room temperature.
• Detected a significant magneto-optic Kerr effect, providing quantitative analysis of the chiral anomaly.

Conclusions:

• The study presents new experimental approaches for quantitative analysis of chiral anomaly.
• Demonstrated room-temperature manipulation of valley polarization, crucial for topological semimetal applications.
• Opens avenues for understanding fundamental properties and applications of chiral fermions.