Perturbative analysis of error amplification for quantum gates' generators

• Error amplification (EA) is a technique to amplify effects of small implementation errors of quantum gates, and currently it is used in advanced tomographic protocols such as Gate-Set Tomography (GST) and Hamiltonian Error-Amplifying Tomography (HEAT). Although EA plays an important role in the protocols, it is still unclear how and which parts of an implementation error of a gate are amplified by an EA gate sequence, except for some simple cases. Here we propose theoretical methods for analyzing such amplification effects of EAs on implementation errors in a perturbative way. By using the method, we clarify dominant quantities characterizing such effects of EA gate sequences.