EXCITONIC AND FREE-CARRIER POLARIZATIONS OF BULK GAAS STUDIED BY FEMTOSECOND COHERENT SPECTROSCOPY

被引：40

作者：

LEITENSTORFER, A

LOHNER, A

RICK, K

LEISCHING, P

ELSAESSER, T

KUHN, T

ROSSI, F

STOLZ, W

PLOOG, K

机构：

[1] MAX BORN INST NICHTLINEARE OPT & KURZZEITSPEKTROSK, D-12489 BERLIN, GERMANY

[2] UNIV STUTTGART, INST THEORET PHYS, D-70550 STUTTGART, GERMANY

[3] UNIV MARBURG, FACHBEREICH PHYS, D-35037 MARBURG, GERMANY

[4] PAUL DRUDE INST HALBLEITERELEKTR, D-10117 BERLIN, GERMANY

[5] UNIV MARBURG, ZENTRUM MAT WISSENSCH, D-35037 MARBURG, GERMANY

来源：

PHYSICAL REVIEW B | 1994年 / 49卷 / 23期

关键词：

D O I：

10.1103/PhysRevB.49.16372

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The transient third-order polarization at the band gap of undoped and p-doped GaAs is investigated by spectrally and temporally resolved four-wave mixing. Excitonic and free-carrier contributions simultaneously excited within the bandwidth of the 100-fs pulses are clearly distinguished by their different spectral envelopes. The excitonic part dominates at carrier densities below 10(16) cm-3 and shows a time evolution governed by exciton-free-carrier scattering and by many-body effects. At higher density, the free-carrier polarization has a strength similar to the exciton contribution and exhibits a spectrum resonant to the femtosecond pulses with a photon-echo-like temporal behavior. The data are analyzed by a numerical solution of the semiconductor Bloch equations including an ensemble Monte Carlo simulation of the scattering dynamics of the carriers. The theoretical model is in good agreement with the experimental results.

引用

页码：16372 / 16380

页数：9

共 29 条

[1] FEMTOSECOND PHOTON-ECHOES FROM BAND-TO-BAND TRANSITIONS IN GAAS [J].