TY - JOUR

T1 - Measurement of Temporal Correlations of the Overhauser Field in a Double Quantum Dot

AU - Reilly, D. J.

AU - Taylor, J M

AU - Laird, E. A.

AU - Petta, J R

AU - Marcus, C M

AU - Hanson, M P

AU - Gossard, A C

PY - 2008/12/1

Y1 - 2008/12/1

N2 - 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 ∼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.

AB - 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 ∼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.

KW - cond-mat.mes-hall,cond-mat.stat-mech

U2 - 10.1103/PhysRevLett.101.236803

DO - 10.1103/PhysRevLett.101.236803

M3 - Journal article

VL - 101

JO - Physical review letters

JF - Physical review letters

SN - 0031-9007

IS - 23

M1 - 236803

ER -