Figure 1

The QSNET network, including the University of Birmingham (UoB), the National Physical Laboratory (NPL), the Imperial College London (ICL) and the University of Sussex (UoS). For each node we indicate the atomic or molecular clock used and to which fundamental constant variations they are sensitive. In the table, we report the wavelength of the clock transitions and the sensitivity coefficients \(K_{\alpha}\) [29, 30] and \(K_{\mu}\), as defined by Eqs. (8) and (9)