Researchers from the UAB and the University of Nottingham, in an article published in Physical Review Letters, have fixed the limits of thermometry, i.e., they have established the smallest possible fluctuation in temperature which can be measured. The researchers have studied the sensitivity of thermometers created with a handful of atoms, small enough to be capable of showing typical quantum-style behaviours.

The researchers characterised these types of probes in detail, devices which could provide an estimation of the temperature with a never before seen precision. To do so, they combined thermodynamic tools with quantum metrology, which deals with ultra-precise measures in quantum systems.

The physicists searched to find the maximum precision which could be achieved in a real situation, in which measuring time could be very brief given unavoidable experimental limitations. In the research, they also observed that these thermometers could maintain a constant sensitivity in a wide range of temperatures by sacrificing some of their precision.

For the authors of the research, "finding a nanothermometer sensitive enough at this scale is a great step forward in the field of nanotechnology, with applications in biology, chemistry, physics and even in the diagnosis and treatment of diseases".