Impurities

Metrology for a Donor Cluster

Objective:

  • Experimental probe of configuration, i.e. number of donors and donor locations, in a donor cluster is needed.
  • Developing a metrology based electron spin resonance (ESR) technology.

Approach:

  • Atomistic tight-binding approach and self-consistent field method is employed for solving donor-cluster wavefunctions.
  • The study object can be generally described as an m-nuclear-spin-1-electron-spin system.
  • The effective spin Hamitonian contains Fermi contact hyperfine, dipolar interaction and Zeeman terms, which determines the ESR spectrum.
  • The configuration can be figured out by comparing experimental and theoretical ESR spectrums.

Results/Impact:

  • Number of ESR peaks goes up with number of donors.
  • Fermi contact hyperfine constants as well as the separation of ESR peaks decrease with the distance between two donors.
  • Given the same donor number and the same donor locations in a cluster, the separations of ESR frequencies decrease with the bound electron number.

Group member involved: