Dangling-bond charge qubit on a silicon surface

Abstract

Two closely spaced dangling bonds (DBs) positioned on a silicon surface and sharing an excess electron are revealed to be a strong candidate for a charge qubit. Based on our study of the coherent dynamics of this qubit, its extremely high tunneling rate ∼1014 s-1 greatly exceeds the expected decoherence rates for a silicon-based system, thereby overcoming a critical obstacle of charge qubit quantum computing (QC). We investigate possible configurations of DB qubits for QC devices. A first-order analysis of coherent dynamics of DBs shows promise in this respect.