MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2009 Dec 11;103(24):245301. doi: 10.1103/PhysRevLett.103.245301. Epub 2009 Dec 7.
We demonstrate spin gradient thermometry, a new general method of measuring the temperature of ultracold atoms in optical lattices. We realize a mixture of spins separated by a magnetic field gradient. Measurement of the width of the transition layer between the two spin domains serves as a new method of thermometry which is observed to work over a broad range of lattice depths and temperatures, including in the Mott insulator regime. We demonstrate the thermometry using ultracold rubidium atoms, and suggest that interesting spin physics can be realized in this system. The lowest measured temperature is 1 nK, indicating that the system has reached the quantum regime, where insulating shells are separated by superfluid layers.
我们展示了自旋梯度测温法，这是一种测量光学晶格中超冷原子温度的新方法。我们实现了磁场梯度分离的自旋混合物。测量两个自旋畴之间的跃迁层的宽度可以作为一种新的测温方法，该方法在广泛的晶格深度和温度范围内都能工作，包括莫特绝缘体制冷区。我们使用超冷铷原子来演示这种测温法，并提出在这个系统中可以实现有趣的自旋物理。测量到的最低温度为 1nK，表明系统已经达到量子区域，在这个区域中，绝缘壳层由超流层隔开。
