Absorption and emission in quantum dots: Fermi surface effects of Anderson excitons

R. W. Helmes, M. Sindel, L. Borda, and J. von Delft
Phys. Rev. B 72, 125301 – Published 1 September 2005

Abstract

Recent experiments measuring the emission of exciton recombination in a self-organized single quantum dot (QD) have revealed that different effects occur when the wetting layer surrounding the QD becomes filled with electrons because the resulting Fermi sea can hybridize with the local electron levels on the dot. Motivated by these experiments, we study an extended Anderson model, which describes a local conduction band level coupled to a Fermi sea, but also includes a local valence band level. We are interested, in particular, in how many-body correlations resulting from the presence of the Fermi sea affect the absorption and emission spectra. Using Wilson’s numerical renormalization group method, we calculate the zero-temperature absorption (emission) spectrum of a QD, which starts from (ends up in) a strongly correlated Kondo ground state. We predict two features: First, we find that the spectrum shows a power-law divergence close to the threshold, with an exponent that can be understood by analogy to the well-known x-ray edge absorption problem. Second, the threshold energy ω0—below which no photon is absorbed (above which no photon is emitted)—shows a marked, monotonic shift as a function of the exciton binding energy Uexc.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
2 More
  • Received 14 February 2005

DOI:https://doi.org/10.1103/PhysRevB.72.125301

©2005 American Physical Society

Authors & Affiliations

R. W. Helmes1, M. Sindel1, L. Borda1,2, and J. von Delft1

  • 1Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität München, 80333 München, Germany
  • 2Research Group “Theory of Condensed Matter,” Hungarian Academy of Sciences and Theoretical Physics Department, Technical University Budapest, H-1521, Hungary

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 72, Iss. 12 — 15 September 2005

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×