Continuous and Pulsed Quantum Zeno Effect

TL;DR

This paper demonstrates the observation and comparison of continuous and pulsed quantum Zeno effects in a Bose-Einstein condensate, showing how measurement strength suppresses quantum state transitions.

Contribution

It provides experimental evidence that continuous and pulsed quantum Zeno effects can be quantitatively compared in a BEC, confirming theoretical predictions about their equivalence under certain conditions.

Findings

Continuous measurements suppress transition rates similarly to pulsed measurements when scaled appropriately.

Transition rate suppression can be increased to as low as 0.005 times the original rate.

Experimental results agree with theoretical predictions of measurement-induced suppression.

Abstract

Continuous and pulsed quantum Zeno effects were observed using a $^{87}$Rb Bose-Einstein condensate(BEC). Oscillations between two ground hyperfine states of a magnetically trapped condensate, externally driven at a transition rate $\omega_R$, were suppressed by destructively measuring the population in one of the states with resonant light. The suppression of the transition rate in the two level system was quantified for pulsed measurements with a time interval $\delta t$ between pulses and continuous measurements with a scattering rate $\gamma$. We observe that the continuous measurements exhibit the same suppression in the transition rate as the pulsed measurements when $\gamma\delta t=3.60(0.43)$, in agreement with the predicted value of 4. Increasing the measurement rate suppressed the transition rate down to $0.005\omega_R$.