A key factor for the performance of sensors is the speed at which the system returns to its initial state after a disturbance or measurement, similar to the taring of a balance. In the quantum sensor under investigation, this corresponds to the transition of electrons from an energetically excited state to the ground state. However, the electrons remain in a kind of metastable intermediate state for a short time. A team of physicists from Julius-Maximilians-Universität Würzburg (JMU) has now directly measured this waiting time in a two-dimensional material: It lasts exactly 24 billionths of a second.

This knowledge is particularly important for quantum technology. It can be used to significantly increase the accuracy of atomic sensors, paving the way for the medical diagnostics of the future, for example. Professor Vladimir Dyakonov, Head of the Chair of Experimental Physics VI (EPVI), was responsible for the study published in the journal Science Advances.