We study a modified version (arguably within reach of present technology) of a typical interferometric measurement scheme so that energy conservation enters in a non-trivial way. In such a case, the measurement accuracy is limited by fundamental bounds due to energy conservation. We characterize the measurement error in relation to physical quantities of the model (such as the finite duration of the measurement scheme) and discuss their relation with the fundamental bounds. In addition to their fundamental relevance, our findings have important practical consequences for optimal resource management in quantum technologies.

Our research was published on PRL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.240202