Metallic excitons

Observation of excitons in one-dimensional metallic single-walled carbon nanotubes.

Excitons are generally believed not to exist in metals because of strong screening by free carriers. Here we demonstrate that excitonic states can in fact be produced in metallic systems of a one-dimensional character. Using metallic single-walled carbon nanotubes as a model system, we show both experimentally and theoretically that electron-hole pairs form tightly bound excitons. The exciton b...

Excitons in electrostatic traps

We consider in-plane electrostatic traps for indirect excitons in coupled quantum wells, where the traps are formed by a laterally modulated gate voltage. An intrinsic obstacle for exciton confinement in electrostatic traps is an in-plane electric field that can lead to exciton dissociation. We propose a design to suppress the in-plane electric field and, at the same time, to effectively confin...

Spin transport of excitons.

We report on observation of the spin transport of spatially indirect excitons in GaAs/AlGaAs coupled quantum wells (CQW). Exciton spin transport over substantial distances, up to several micrometers in the present work, is achieved due to orders of magnitude enhancement of the exciton spin relaxation time in CQW with respect to conventional quantum wells.

Excitons in nanoscale systems.

Nanoscale systems are forecast to be a means of integrating desirable attributes of molecular and bulk regimes into easily processed materials. Notable examples include plastic light-emitting devices and organic solar cells, the operation of which hinge on the formation of electronic excited states, excitons, in complex nanostructured materials. The spectroscopy of nanoscale materials reveals d...

Quasienergy Spectroscopy of Excitons