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

Journal article

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.

Authors: Reilly, D; Taylor, J; Laird, E; Petta, JR; Marcus, C

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 101
• Issue: 23
• Pages: 236803
• Publication date: 2008-12-01
• DOI: 10.1103/physrevlett.101.236803
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English