Spin-polarized PL and raman spectroscopy of nanocrystal quantum dots in high magnetic fields

M. Furis, P. D. Robbins, T. Barrick, M. Petruska, V. I. Klimov, S. A. Crooker

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The ground state spectrum of an exciton in a quantum dot is strongly modified by the effects of quantum confinement and the correspondingly enhanced electron-hole exchange energy. Elucidation of this exciton spin structure via its evolution in applied magnetic field is the primary goal of this work. To this end we have developed techniques for spin-polarized resonant photoluminescence (PL) excitation spectroscopy in high magnetic fields. Using a tunable narrowband dye laser and a fiber-coupled probe designed for use in high-field magnets to 33 Tesla, we resonantly inject spin-polarized electrons and holes into nanocrystal quantum dots, and subsequently measure the quasi-resonant PL from either spin-up or spin-down excitons vs. magnetic field, at temperatures down to 1.7 K. The data shows clear evidence of low-energy Raman signals - e.g., sharp peaks of quantized acoustic phonons are well-resolved at energies <1 meV from the excitation laser. Most notably, a sharp Raman-like feature appears in the PL spectrum at high magnetic fields >10 Tesla, at an energy of a few meV that is systematically dependent on nanocrystal radius (1.4-2.9 nm). The energy of this high field mode corresponds to the Zeeman splitting of the lowest optically allowed excitonic state in the quantum dots.

Original languageEnglish
Title of host publicationPHYSICS OF SEMICONDUCTORS
Subtitle of host publication27th International Conference on the Physics of Semiconductors, ICPS-27
Pages709-710
Number of pages2
DOIs
Publication statusPublished - Jun 30 2005
EventPHYSICS OF SEMICONDUCTORS: 27th International Conference on the Physics of Semiconductors, ICPS-27 - Flagstaff, AZ, United States
Duration: Jul 26 2004Jul 30 2004

Publication series

NameAIP Conference Proceedings
Volume772
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

OtherPHYSICS OF SEMICONDUCTORS: 27th International Conference on the Physics of Semiconductors, ICPS-27
CountryUnited States
CityFlagstaff, AZ
Period7/26/047/30/04

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Furis, M., Robbins, P. D., Barrick, T., Petruska, M., Klimov, V. I., & Crooker, S. A. (2005). Spin-polarized PL and raman spectroscopy of nanocrystal quantum dots in high magnetic fields. In PHYSICS OF SEMICONDUCTORS: 27th International Conference on the Physics of Semiconductors, ICPS-27 (pp. 709-710). (AIP Conference Proceedings; Vol. 772). https://doi.org/10.1063/1.1994303