Qiao Mu, Wang Ye, Cai Zhengyang, Du Botao, Wang Pengfei, Luan Chunyang, Chen Wentao, Noh Heung-Ryoul, Kim Kihwan
Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China.
Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA.
Phys Rev Lett. 2021 Jan 15;126(2):023604. doi: 10.1103/PhysRevLett.126.023604.
We theoretically and experimentally investigate double-electromagnetically-induced transparency (double-EIT) cooling of two-dimensional ion crystals confined in a Paul trap. The double-EIT ground-state cooling is observed for ^{171}Yb^{+} ions with a clock state, for which EIT cooling has not been realized like many other ions with a simple Λ scheme. A cooling rate of n[over ¯][over ˙]=34(±1.8) ms^{-1} and a cooling limit of n[over ¯]=0.06(±0.059) are observed for a single ion. The measured cooling rate and limit are consistent with theoretical predictions. We apply double-EIT cooling to the transverse modes of two-dimensional (2D) crystals with up to 12 ions. In our 2D crystals, the micromotion and the transverse mode directions are perpendicular, which makes them decoupled. Therefore, the cooling on transverse modes is not disturbed by micromotion, which is confirmed in our experiment. For the center of mass mode of a 12-ion crystal, we observe a cooling rate and a cooling limit that are consistent with those of a single ion, including heating rates proportional to the number of ions. This method can be extended to other hyperfine qubits, and near ground-state cooling of stationary 2D crystals with large numbers of ions may advance the field of quantum information sciences.
我们从理论和实验上研究了囚禁在保罗阱中的二维离子晶体的双电磁诱导透明（双EIT）冷却。对于具有钟态的(^{171}Yb^{+})离子，观察到了双EIT基态冷却，对于这种离子，不像许多具有简单Λ方案的其他离子那样尚未实现EIT冷却。对于单个离子，观察到冷却速率(\overline{n}\dot{=}34(±1.8),ms^{-1})和冷却极限(\overline{n}=0.06(±0.059))。测量的冷却速率和极限与理论预测一致。我们将双EIT冷却应用于多达12个离子的二维（2D）晶体的横向模式。在我们的二维晶体中，微运动和横向模式方向是垂直的，这使得它们解耦。因此，横向模式上的冷却不受微运动的干扰，这在我们的实验中得到了证实。对于12离子晶体的质心模式，我们观察到的冷却速率和冷却极限与单个离子的一致，包括与离子数成比例的加热速率。这种方法可以扩展到其他超精细量子比特，并且大量离子的静止二维晶体的近基态冷却可能会推动量子信息科学领域的发展。
