Details

Autor(en) / Beteiligte

• Reilly, D J
• Taylor, J M
• Laird, E A
• Petta, J R
• Marcus, C M
• Hanson, M P
• Gossard, A C

Titel

Measurement of temporal correlations of the overhauser field in a double quantum dot

Ist Teil von

• Physical review letters, 2008-12, Vol.101 (23), p.236803-236803, Article 236803

Ort / Verlag

United States

Erscheinungsjahr

2008

Link zum Volltext

Quelle

APS_美国物理学会过刊

Beschreibungen/Notizen

• In quantum dots made from materials with nonzero nuclear spins, hyperfine coupling creates a fluctuating effective Zeeman field (Overhauser field) felt by electrons, which can be a dominant source of spin qubit decoherence. We characterize the spectral properties of the fluctuating Overhauser field in a GaAs double quantum dot by measuring correlation functions and power spectra of the rate of singlet-triplet mixing of two separated electrons. Away from zero field, spectral weight is concentrated below 10 Hz, with approximately 1/f2 dependence on frequency f. This is consistent with a model of nuclear spin diffusion, and indicates that decoherence can be largely suppressed by echo techniques.