Fundamental limits on low-temperature quantum thermometry with finite resolution

Understand

While the ability to measure low temperatures accurately in quantum systems is important in a wide range of experiments, the possibilities and the fundamental limits of quantum thermometry are not yet fully understood theoretically.

• Here we develop a general approach to low-temperature quantum thermometry, taking into account restrictions arising not only from the sample but also from the measurement process.
• We derive a fundamental bound on the minimal uncertainty for any temperature measurement that has a finite resolution.
• A similar bound can be obtained from the third law of thermodynamics.