Fig. 2: Bias dependence of electron and nuclear spin dynamics. | npj Quantum Information

Fig. 2: Bias dependence of electron and nuclear spin dynamics.

From: Fundamental limits of electron and nuclear spin qubit lifetimes in an isolated self-assembled quantum dot

Fig. 2

a Bias dependence of resonance fluorescence (ResFl) intensity IResFl in a QD sample with tB = 37 nm. At Bz = 0 T (triangles) a clear Coulomb blockade (1e plateau) is observed, with IResFl decreasing when the dot is emptied (0e, VS ≲ 0.1 V) or filled with a second electron (2e, VS ≳ 0.33 V). At non-zero Bz = 1 T (circles) and Bz = 8 T (squares) the centre of the 1e plateau is suppressed due to spin ‘shelving’, leaving two peaks arising from resonant tunnel coupling to the Fermi reservoir. b Bias dependence of the electron spin relaxation rate measured at Bz = 1 T (circles) and Bz = 8 T (squares). c Bias dependence of the nuclear spin relaxation rate measured for the same QD as in a and b. Note the offset in the horizontal axis, which is likely due to additional electric fields arising from the optically generated trapped charges near the QD. Vertical dashed lines separate different charge states 0e, 1e, 2e. d–f Same as a–c but for a QD from a thick-barrier sample (tB = 52 nm). All error bars are 95% confidence intervals.

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