Abstract
We measure the hyperfine interaction of the valence band hole with nuclear spins in single semiconductor quantum dots. Detection of photoluminescence (PL) of both “bright” and “dark” excitons enables direct measurement of the Overhauser shift of states with the same electron but opposite hole spin projections. We find that the hole hyperfine constant is of that of the electron and has the opposite sign. By measuring the degree of circular polarization of the PL, an upper limit to the contribution of the heavy-light hole mixing to the measured value of the hole hyperfine constant is deduced. Our results imply that environment-independent hole spins are not realizable in III-V semiconductor, a result important for solid-state quantum information processing using hole spin qubits.
- Received 7 September 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.027402
© 2011 The American Physical Society