Long–lived femtosecond photon echo in thin films on localized exciton states at room temperature

N.S Vashurin,V.O Kompanets,I.I Popov,S.V Chekalin,S.E Putilin,V.V Samartsev,M.G Gladush,K.R Karimullin,A.V Naumov,A.A Kalachev

doi:10.1051/epjconf/201716103007

Abstract

Long–lived femtosecond photon echo was excited at room temperature in a two–photon regime on the charged exciton states (trion type) localized on the surface defects of a three–layer textured ZnO/Si(B)/Si(P) film with the thickness of each layer at 100 nm in a longitudinal uniform magnetic field. The irreversible longitudinal relaxation time T 1 for the long–lived photon echo regime was of the order of 40 ps, whereas when measured with the help of the stimulated photon echo generated in the single–photon mode, the value was found not to exceed 600 fs.

Highlights

In the presence of a longitudinal homogeneous magnetic field of the echo, a long-lived photon echo effect was observed in a three-layer film (Fig. 1), in single-layer films it did not
When an echo signal corresponding to the synchronism conditions for four-wave mixing and the stimulated photon echo excited in the single-photon mode was observed, the usual femtosecond stimulated photon echo (SPE) was recorded
* Corresponding author: Popov@volgatech.net longitudinal relaxation T1 for the regime of the long-lived photon echo was about 40 ps, whereas when it was measured with the help of the SPE generated in single-photon mode, a value of no more than 600 fs was obtained

Summary

Introduction

In the presence of a longitudinal homogeneous magnetic field of the echo, a long-lived photon echo effect was observed in a three-layer film (Fig. 1), in single-layer films it did not. When an echo signal corresponding to the synchronism conditions for four-wave mixing and the stimulated photon echo excited in the single-photon mode was observed, the usual femtosecond stimulated photon echo (SPE) was recorded.

Results

Conclusion