Excitons in a sentence

E. I. Rashba, Self-trapping of excitons, in: Excitons (North-Holland, Amsterdam, 1982), p. 547. This means that spectral lines of free excitons and wide bands of self-trapped excitons can be seen simultaneously in absorption and luminescence spectra.

Exciton condensates have been seen in a double quantum well systems. citation Spatially Direct and Indirect Excitons Normally, excitons in a semiconductor have a very short lifetime due to the close proximity of the electron and hole.

This phenomenon is generic and applicable both to the large radius (Wannier-Mott) excitons and molecular (Frenkel) excitons.

When is focused on TMDs, particles known as excitons are generated.

A new connection is formed, almost instantaneously, with special energy states – known as interlayer excitons – that exist in both layers and determine the properties of the new material.

Classification Excitons may be treated in two limiting cases, depending on the properties of the material in question.

Excitons are self-trapped when and are large, and then the spatial size of the barrier is large compared with the lattice spacing.

Excitons, electron-hole pairs, were predicted to condense at low temperature and high density by Boer et al. in 1961.

However, when the coupling is strong, excitons can be self-trapped.

If a large density of excitons is created in a material, they can interact with one another to form an electron-hole liquid, a state observed in k-space indirect semiconductors.

If this coupling is weak as in typical semiconductors such as GaAs or Si, excitons are scattered by phonons.

In contrast to ordinary (spatially direct), these spatially indirect excitons can have large spatial separation between the electron and hole, and thus possess a much longer lifetime.

It is not applicable, for example, for the condensates of excitons, magnons and photons, where the critical temperature is up to room one.

Magnons, Excitons, and Polaritons have integer spin and form condensates.

Often there is more than one band to choose from for the electron and the hole leading to different types of excitons in the same material.

Second, there exists a self-trapping barrier separating free and self-trapped states, hence, free excitons are metastable.

The concept of excitons was first proposed by Yakov Frenkel in 1931, citation when he described the excitation of atoms in a lattice of insulators.

The hallmark of molecular excitons in organic molecular crystals are doublets and/or triplets of exciton absorption bands strongly polarized along crystallographic axes.

They are also known as large excitons.

Third, this barrier enables coexistence of free and self-trapped states of excitons.