Streed Erik W, Mun Jongchul, Boyd Micah, Campbell Gretchen K, Medley Patrick, Ketterle Wolfgang, Pritchard David E
Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2006 Dec 31;97(26):260402. doi: 10.1103/PhysRevLett.97.260402. Epub 2006 Dec 27.
Continuous and pulsed quantum Zeno effects were observed using a 87Rb Bose-Einstein condensate. 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 deltat 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 gammadeltat=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).
利用87Rb玻色-爱因斯坦凝聚体观测到了连续和脉冲量子芝诺效应。在以跃迁率ω(R)进行外部驱动的情况下，通过用共振光对磁阱凝聚体的两个基态超精细态之一的布居进行破坏性测量，抑制了这两个态之间的振荡。对于脉冲间隔为Δt的脉冲测量和散射率为γ的连续测量，对二能级系统中跃迁率的抑制进行了量化。我们观察到，当γΔt = 3.60(0.43)时，连续测量在跃迁率上表现出与脉冲测量相同的抑制效果，这与预测值4相符。提高测量率可将跃迁率抑制至0.005ω(R)。
