Fig. 4: Measuring the lifetime of the purified bath-state via qubit-state autocorrelation.
From: Anti-Zeno purification of spin baths by quantum probe measurements
a The pulse sequence used for the measurement. After the conditional bath state purification by CT M0,4, we allow a waiting time td (plotted on a log-scale) and then measure again the probability of obtaining an identical measurement result for the qubit. b The probability of obtaining the result 0 after a long waiting (delay) time td for bath state preparations via M0,4 (orange) is shown for measurement intervals τ = 1.2 μs. The flat part of the orange curve marks a long auto-correlation time for the qubit. These probabilities are compared with the case without bath purification (red), where the auto-correlation time is much shorter. The effective lifetime of the bath, following purification, is seen to extend towards the \({T}_{1}^{e}\) lifetime of the probe. Further details on the error bar analysis are given in the “Methods” section.
