Tunable Kondo effect in a single donor atom.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 20041698.
- Also identified by DOI 10.1021/nl9031132.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The Kondo effect has been observed in a single gate-tunable atom. The measurement device consists of a single As dopant incorporated in a silicon nanostructure. The atomic orbitals of the dopant are tunable by the gate electric field. When they are tuned such that the ground state of the atomic system becomes a (nearly) degenerate superposition of two of the silicon valleys, an exotic and hitherto unobserved valley Kondo effect appears. Together with the "regular" spin Kondo, the tunable valley Kondo effect allows for reversible electrical control over the symmetry of the Kondo ground state from an SU(2) to an SU(4) configuration.