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Related Experiment Video

Updated: Jun 13, 2026

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
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Light amplification without population inversion in magnetised monolayer graphene.

Forough Bozorgzadeh

    Optics Express
    |August 13, 2025
    PubMed
    Summary

    We demonstrate optical gain without population inversion in Landau-quantized graphene using a simple approach. This method is suitable for developing advanced graphene-based terahertz optical amplifiers and lasers.

    Area of Science:

    • Condensed Matter Physics
    • Quantum Optics
    • Materials Science

    Background:

    • Population inversion is typically required for light amplification.
    • Graphene exhibits unique electronic properties due to Landau quantization.
    • Achieving optical gain without population inversion is a significant challenge.

    Purpose of the Study:

    • To propose a novel method for achieving light amplification without population inversion.
    • To investigate the optical properties of Landau-quantized graphene under specific field interactions.
    • To explore potential applications in graphene-based optoelectronic devices.

    Main Methods:

    • Numerical solution of the density matrix equation in the transient regime.
    • Analysis of interactions between coherent and incoherent fields in a three-level system.

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  • Derivation of analytical expressions using perturbation theory.

    • Main Results:

    • Demonstrated optical gain without population inversion in Landau-quantized graphene.
    • Obtained steady-state populations in Landau levels.
    • Derived coherence terms related to optical gain.

    Conclusions:

    • The proposed system enables optical gain without population inversion.
    • This approach is applicable to graphene-based optical amplifiers and lasers.
    • The technology is particularly relevant for terahertz frequency applications.