Abstract
Understanding the dynamics of excitons in two-dimensional semiconductors requires a theory that incorporates the essential physics distinct from their three-dimensional counterparts. In addition to the modified dielectric environment, single-particle states with strongly nonparabolic dispersion appear in many two-dimensional band structures, so that “effective mass” is ill-defined. Focusing on electrostatically biased bilayer graphene as an example where quartic (and higher) dispersion terms are necessary, we present a semianalytic theory used to investigate the properties of ground and excited excitonic states. This includes determination of relative oscillator strengths and magnetic moments (valley -factors) which can be directly compared to recent experimental measurements.
- Received 29 August 2018
- Revised 6 November 2018
DOI:https://doi.org/10.1103/PhysRevB.99.035429
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