Longitudinal-transverse splitting and fine structure of Fermi polarons in two-dimensional semiconductors

Abstract

Interaction of excitons with resident charge carriers in semiconductors gives rise to bound three-particle complexes, trions, whose optical response is conveniently described in the framework of many-body correlated Fermi polaron states. These states are formed as a result of correlation of photocreated trion with the Fermi sea hole and possess the angular momentum component of $\pm 1$ depending on the helicity of the photon. We study theoretically the energy spectrum fine structure of Fermi polarons in two-dimensional semiconductors based on transition metal dichalcogenides. We demonstrate both by the symmetry analysis and microscopic calculation that the Fermi polarons with nonzero in-plane wavevector $\mathbf{k}$ are split, similarly to the neutral exciton states, into the linearly polarized longitudinal and transverse, with respect to the $\mathbf{k}$, states. The origin of this longitudinal-transverse splitting is the long-range electron-hole exchange interaction that can be also described as the interaction of Fermi polarons with their induced electromagnetic field. The effective Hamiltonian describing the Fermi polaron fine structure is derived, and its parameters are determined from the microscopic model.

Submitted to a special issue of J. Lumin. in homage to Profs. F. Auzel and A. Kaplyanskii; 12 pages, 3 figures

References in corpus (8)

• Many-Body Theory of Trion Absorption Features in Two-Dimensional Semiconductors
• Phonon Sidebands in Transition Metal Dichalcogenides
• Hexcitons and oxcitons in monolayer WSe${}_2$
• A Many-Body Theory of the Optical Conductivity of Excitons and Trions in Two-Dimensional Materials
• Electron recoil effect in electrically tunable MoSe2 monolayers
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• Light-matter coupling and non-equilibrium dynamics of exchange-split trions in monolayer WS2

Cited by in corpus (3)

• Electromagnetic field assisted exciton diffusion in moiré superlattices
• Excitons and trions in CrSBr bilayers
• Terahertz radiation induced attractive-repulsive Fermi polaron conversion in transition metal dichalcogenide monolayers