Longitudinal and Transverse Excitons in Semiconductors

Denisov, M. M.; Макаров, В. М.

doi:10.1002/pssb.2220560102

Cited by 130 publications

(69 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…. 10 meV short-range splitting of dark and bright excitons ∼ 10's of meV hole recombination (Bir and Pikus, 1974;Denisov and Makarov, 1973;Goupalov et al, 1998): The bright exciton can be considered as a microscopic dipole which produces an electric field, the back-action of this field on the exciton is the long-range electron-hole exchange interaction. On a formal level, it corresponds to the decomposition of the Coulomb interaction up to the dipole term and calculation of its matrix element on the antisymmetrized Bloch functions (Andreani, 1995).…”

Section: Coulomb Term Impactmentioning

confidence: 99%

Excitons in atomically thin transition-metal dichalcogenides

et al. 2014

View full text Add to dashboard Cite

Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality and crystal symmetry. The family of semiconducting transition metal dichalcogenides is an especially promising platform for fundamental studies of two-dimensional (2D) systems, with potential applications in optoelectronics and valleytronics due to their direct band gap in the monolayer limit and highly efficient light-matter coupling. A crystal lattice with broken inversion symmetry combined with strong spin-orbit interactions leads to a unique combination of the spin and valley degrees of freedom. In addition, the 2D character of the monolayers and weak dielectric screening from the environment yield a significant enhancement of the Coulomb interaction. The resulting formation of bound electron-hole pairs, or excitons, dominates the optical and spin properties of the material. Here we review recent progress in our understanding of the excitonic properties in monolayer TMDs and lay out future challenges. We focus on the consequences of the strong direct and exchange Coulomb interaction, discuss exciton-light interaction and effects of other carriers and excitons on electron-hole pairs in TMDs. Finally, the impact on valley polarization is described and the tuning of the energies and polarization observed in applied electric and magnetic fields is summarized.

show abstract

Section: Coulomb Term Impactmentioning

confidence: 99%

Excitons in atomically thin transition-metal dichalcogenides

et al. 2014

View full text Add to dashboard Cite

show abstract

“…LRE electron-hole interaction in bulk semiconductors was investigated almost 40 years ago [14][15][16] and it is now well established that LRE splits the energy levels of bright excitons. For example, in zinc-blende direct band-gap semiconductors with fourfold-degenerate valence band ⌫ 8v and twofolddegenerate conduction band ⌫ 6c , the ground-state exciton is eightfold degenerate.…”

Section: Introductionmentioning

confidence: 99%

Theory of exciton fine structure in semiconductor quantum dots: Quantum dot anisotropy and lateral electric field

Kadantsev

Hawrylak

2010

Phys. Rev. B

View full text Add to dashboard Cite

Theory of exciton fine structure in semiconductor quantum dots and its dependence on quantum-dot anisotropy and external lateral electric field is presented. The effective exciton Hamiltonian including long-range electron-hole exchange interaction is derived within the k · p effective-mass approximation. The exchange matrix elements of the Hamiltonian are expressed explicitly in terms of electron and hole envelope functions. The matrix element responsible for the "bright" exciton splitting is identified and analyzed. An excitonic fine structure for a model quantum dot with quasi-two-dimensional anisotropic harmonic oscillator confining potential is analyzed as a function of the shape anisotropy, size, and applied lateral electric field.

show abstract

“…The component with K = 0 describes the experimentally observed splitting between ortho and para excitons of 12 meV [34][35][36]. Therefore, we set…”

Section: A Analytic Exchange Interactionmentioning

confidence: 99%

K-dependent exchange interaction of the1Sorthoexciton inCu2O

Schweiner¹,

Main²,

Uihlein³

2016

Phys. Rev. B

View full text Add to dashboard Cite

When treating the exchange interaction of Wannier excitons, usually only the leading terms of the analytic and the nonanalytic exchange interaction are considered. However, higher order terms can lead to a splitting of exciton states, for which reason a splitting of the 1S exciton in cuprous oxide (Cu2O) depending on its total momentum K has been attributed to a K dependent analytic exchange interaction by Dasbach et al [Phys. Rev. Lett. 91, 107401 (2003)]. Going beyond the common treatment of the exchange interaction, we derive the correct expressions for these K dependent higher order terms using k · p perturbation theory. We prove that the appearance of a K dependent exchange interaction is inseparably connected with a K independent exchange interaction of P and D excitons. We estimate the magnitude of these terms for Cu2O from microscopic calculations and show that they are far too small to explain the observed K dependent splitting. Instead, this splitting has to be treated in terms of the dispersion of the excitons. Furthermore, we prove the occurence of a coupling between longitudinal and transverse excitons in Cu2O due to the K dependent nonanalytic exchange interaction.

show abstract

Longitudinal and Transverse Excitons in Semiconductors

Cited by 130 publications

References 26 publications

Excitons in atomically thin transition-metal dichalcogenides

Excitons in atomically thin transition-metal dichalcogenides

Theory of exciton fine structure in semiconductor quantum dots: Quantum dot anisotropy and lateral electric field

K-dependent exchange interaction of the1Sorthoexciton inCu2O

Contact Info

Product

Resources

About