Relaxation and readout visibility of a singlet-triplet qubit in an Overhauser field gradient

TY - JOUR

T1 - Relaxation and readout visibility of a singlet-triplet qubit in an Overhauser field gradient

AU - Barthel, C.

AU - Medford, J.

AU - Bluhm, H.

AU - Yacoby, A.

AU - Marcus, Charles M.

AU - hanson, M.P.

AU - Gossard, A.C.

PY - 2012/1/11

Y1 - 2012/1/11

N2 - Using single-shot charge detection in a GaAs double quantum dot, we investigate spin relaxation time (T 1) and readout visibility of a two-electron singlet-triplet qubit following single-electron dynamic nuclear polarization (DNP). For magnetic fields up to 2 T, the DNP cycle is in all cases found to increase Overhauser field gradients, which in turn decrease T 1 and, consequently, reduce readout visibility. This effect was previously attributed to a suppression of singlet-triplet dephasing under a similar DNP cycle. A model describing relaxation after singlet-triplet mixing agrees well with experiment. Effects of pulse bandwidth on visibility are also investigated.

AB - Using single-shot charge detection in a GaAs double quantum dot, we investigate spin relaxation time (T 1) and readout visibility of a two-electron singlet-triplet qubit following single-electron dynamic nuclear polarization (DNP). For magnetic fields up to 2 T, the DNP cycle is in all cases found to increase Overhauser field gradients, which in turn decrease T 1 and, consequently, reduce readout visibility. This effect was previously attributed to a suppression of singlet-triplet dephasing under a similar DNP cycle. A model describing relaxation after singlet-triplet mixing agrees well with experiment. Effects of pulse bandwidth on visibility are also investigated.

U2 - 10.1103/PhysRevB.85.035306

DO - 10.1103/PhysRevB.85.035306

M3 - Journal article

SN - 2469-9950

VL - 85

SP - 035306

JO - Physical Review B

JF - Physical Review B

IS - 3

ER -