Observation of the linear Stark effect in a single acceptor in Si

The Stark splitting of a single fourfold degenerate impurity located within the built-in potential of a metal-semiconductor contact is investigated using low temperature transport measurements. A model is developed and used to analyze transport as a function of temperature, bias voltage, and magnetic field. Our data is consistent with a boron impurity. We report g factors of g(1/2)=1.14 and g(3/2)=1.72 and a linear Stark splitting 2 Delta of 0.1 meV.