Preferences help
enabled [disable] Abstract
Number of results
2003 | 104 | 2 | 113-122
Article title

Ultrafast Coherent Terahertz Spectroscopy in High Magnetic Fields and Directed Energy Flows in Quantum Dot Assemblies

Title variants
Languages of publication
We describe the design, construction, and use of fiber-coupled terahertz antennas for performing ultrafast coherent THz spectroscopy directly in the cryogenic bore of high-field magnets. With an aim towards measuring the high-frequency (100 GHz to 2000 GHz) complex conductivity of correlated electron materials in the regime of low temperatures and high magnetic fields, these miniature THz emitters and receivers are demonstrated to work down to 1.5 K and up to 18 T, for eventual use in higher-field magnets. Results from a variety of semiconducting and superconducting samples are presented. This paper also describes a separate effort towards achieving coupling between colloidal semiconductor nanocrystal quantum dots, wherein we realize and study inter-dot communication via resonant (Förster) energy transfer. We present studies of the dynamics of resonant energy transfer in monodisperse and energy gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time- and spectrally-resolved photoluminescence data directly reveal the energy-dependent transfer rate of excitons from smaller to larger dots. Results from layered nanocrystal quantum dot assemblies demonstrate unidirectional energy flows, a first step towards artificial light-harvesting structures. Lastly, time-resolved studies at millikelvin temperatures elucidate the nature of ground-state"dark" excitons in these quantum dots.
  • National High Magnetic Field Laboratory, Los Alamos, NM 87545, USA
  • National High Magnetic Field Laboratory, Los Alamos, NM 87545, USA
  • Chemistry Division, Los Alamos, NM 87545, USA
  • Chemistry Division, Los Alamos, NM 87545, USA
  • 1. P.R. Smith, D.H. Auston, M.C. Nuss, IEEE J. Quantum Electron., QE-24, 255, 1988; C. Fattinger, D. Grischkowsky, Appl. Phys. Lett., 54, 490, 1989
  • 2. See, e.g., papers by M.C. Nuss, and by D. Grischkowsky
  • 3. S.A. Crooker, Rev. Sci. Instrum., 73, 3258, 2002
  • 4. S.A. Crooker, J.A. Hollingsworth, S. Tretiak, V.I. Klimov, Phys. Rev. Lett., 89, 186802, 2002
  • 5. S.A. Crooker, T. Barrick, J.A. Hollingsworth, V.I. Klimov, Appl. Phys. Lett., 82, 2793, 2003
  • 6. Al.L. Efros, M. Rosen, M. Kuno, M. Nirmal, D.J. Norris, M. Bawendi, Phys. Rev. B, 54, 4843, 1996
Document Type
Publication order reference
YADDA identifier
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.