Giant Hall Photoconductivity in Narrow-Gapped Dirac Materials

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Carrier dynamics are influenced by Berry curvature in gapped Dirac materials (GDMs).
• Berry curvature naturally arises in GDMs, particularly those with small band gaps.

Purpose of the Study:

• To investigate the enhanced photoresponse in GDMs due to Berry curvature.
• To explore the potential of Berry curvature-induced Hall photoconductivity for optoelectronics.

Main Methods:

• Theoretical analysis of carrier dynamics in GDMs under circularly polarized light.
• Modeling of Hall photoconductivity and its dependence on Berry curvature and band gap.

Main Results:

• A giant and saturable Hall photoconductivity is observed in GDMs with small band gaps.
• Berry curvature-induced Hall photoconductivity enhances longitudinal carrier transport, unlike magnetic field-induced Hall effect.
• Hall conductivity per incident irradiance increases by up to 6 orders of magnitude from visible to far-infrared regimes.

Conclusions:

• Narrow-gap GDMs exhibit unique physics driven by Berry curvature.
• Berry curvature offers a novel mechanism for helicity-dependent photoresponse.
• GDMs present promising applications for infrared and terahertz optoelectronics.