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Title

Three-dimensional electronic spectroscopy of excitons in asymmetric double quantum wells

Author(s)

Davis, J. A.;  Hall, C. R.;  Dao, L. V.;  Nugent, K. A.;  Quiney, H. M.;  Tan, H. H.;  Jagadish, C.

Abstract

We demonstrate three-dimensional (3D) electronic spectroscopy of excitons in a double quantum well system using a three-dimensional phase retrieval algorithm to obtain the phase information that is lost in the measurement of intensities. By extending the analysis of two-dimensional spectroscopy to three dimensions, contributions from different quantum mechanical pathways can be further separated allowing greater insight into the mechanisms responsible for the observed peaks. By examining different slices of the complete three-dimensional spectrum, not only can the relative amplitudes be determined, but the peak shapes can also be analysed to reveal further details of the interactions with the environment and inhomogeneous broadening. We apply this technique to study the coupling between two coupled quantum wells, 5.7 nm and 8 nm wide, separated by a 4 nm barrier. Coupling between the heavy-hole excitons of each well results in a circular cross-peak indicating no correlation of the inhomogeneous broadening. An additional cross-peak is isolated in the 3D spectrum which is elongated in the diagonal direction indicating correlated inhomogeneous broadening. This is attributed to coupling of the excitons involving the two delocalised light-hole states and the electron state localised on the wide well. The attribution of this peak and the analysis of the peak shapes is supported by numerical simulations of the electron and hole wavefunctions and the three-dimensional spectrum based on a density matrix approach. An additional benefit of extending the phase retrieval algorithm from two to three dimensions is that it becomes substantially more reliable and less susceptible to noise as a result of the more extensive use of a priori information.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Centre for Atom Optics and Ultrafast Spectroscopy

Source

Journal of Chemical Physics, Vol. 135, no. 4 (Jul 2011), article no. 044510

Publication year

2011

FOR Code(s)

0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics;  0306 Physical Chemistry (Incl. Structural);  0904 Chemical Engineering

Keyword(s)

3D spectroscopy;  Double quantum well;  Electronic spectroscopy;  Excitons;  Three-dimensional spectroscopy

Publisher

American Institute of Physics

ISSN

0021-9606

Publisher URL

http://dx.doi.org/10.1063/1.3613679

Copyright

Copyright © 2011 American Institute of Physics. The published version of the paper is reproduced here in accordance with the copyright policy of the publisher.

Additional information

The authors acknowledge support from the Australian Research Council and the Australian National Fabrication Facility.

Full text

Peer reviewed