| AVS 66th International Symposium & Exhibition | |
| Materials and Processes for Quantum Information, Computing and Science Focus Topic | Tuesday Sessions |
| Session QS+2D+EM+MN+NS-TuA |
| Session: | Materials for Quantum Sciences |
| Presenter: | Rebekah Smith, The Ohio State University |
| Authors: | R. Smith, The Ohio State University A. Benjamin, The Ohio State University J.A. Gupta, The Ohio State University |
| Correspondent: | Click to Email |
Rare earth dopants in III-V semiconductors are of interest as high quality optical sources due to the preservation of sharp intra-f-shell transitions. The long optical coherence lifetime and narrow energy width of these transitions, at 1.54 um, make them a candidate for quantum communication. Here we investigate Er interactions with host GaAs (110) surface with atomic resolution using STM. Er atoms were deposited via electron beam evaporation onto the GaAs surface at 5 K. We find three different Erad configurations with varying abundance upon deposition, each with a different surface site location. All three configurations exhibit long-range depressions in STM topographic images, attributed to band bending associated with a positive adatom charge state. Individual Er adatoms can be switched between these states by applying a positive voltage pulse with the STM tip. Tunneling spectroscopy on Er adsorbed at the interstitial sites reveals prominent states within the GaAs bandgap, but no evidence of sharp f-shell transitions inferred from bulk optical studies. We also form substitutional ErGa by applying a larger positive voltage pulse. Substitutional Er appears neutral, which we attribute to it being isoelectronic with Ga. This work acknowledges funding from the DOE (DE-SC0016379).