Physicists from Kaiserslautern have succeeded for the first time in using a single cesium atom as a sensor for ultra-cold temperatures. The atom was in a rubidium gas cooled down to near absolute zero.
They used quantum states (spin or angular momentum) of the atom to measure the temperature of an ultra-cold gas and the magnetic field, with a particularly high sensitivity. The team has investigated whether the spin states (seven different orientations) of the cesium atom can be used to gain information, for example about the gas temperature.
This is an important step toward measuring sensitive quantum systems with as little perturbation as possible, which is of interest for future applications in quantum technology.
The work was published in the journal Physical Review X. (Phys.org)