Windey Dominik, Gonzalez-Ballestero Carlos, Maurer Patrick, Novotny Lukas, Romero-Isart Oriol, Reimann René
Photonics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.
Phys Rev Lett. 2019 Mar 29;122(12):123601. doi: 10.1103/PhysRevLett.122.123601.
We experimentally realize cavity cooling of all three translational degrees of motion of a levitated nanoparticle in vacuum. The particle is trapped by a cavity-independent optical tweezer and coherently scatters tweezer light into the blue detuned cavity mode. For vacuum pressures around 10^{-5} mbar, minimal temperatures along the cavity axis in the millikelvin regime are observed. Simultaneously, the center-of-mass (c.m.) motion along the other two spatial directions is cooled to minimal temperatures of a few hundred millikelvin. Measuring temperatures and damping rates as the pressure is varied, we find that the cooling efficiencies depend on the particle position within the intracavity standing wave. This data and the behavior of the c.m. temperatures as functions of cavity detuning and tweezer power are consistent with a theoretical analysis of the experiment. Experimental limits and opportunities of our approach are outlined.
我们通过实验实现了真空中悬浮纳米粒子三个平动自由度的腔冷却。该粒子由与腔无关的光镊捕获，并将光镊光相干散射到失谐的腔模中。对于约10⁻⁵ 毫巴的真空压力，观察到沿腔轴方向在毫开尔文范围内的最低温度。同时，沿其他两个空间方向的质心运动被冷却到几百毫开尔文的最低温度。通过改变压力测量温度和阻尼率，我们发现冷却效率取决于腔内驻波中粒子的位置。这些数据以及质心温度随腔失谐和光镊功率的变化行为与该实验的理论分析一致。我们概述了该方法的实验限制和机遇。
