Physical gate-set tomography

Physical models of quantum gates can directly incorporate experimental degrees of freedom, such as laser power or microwave phase, but the forward simulation required to use these models can result in impractical overhead in computational time. In this poster, we develop a method for efficient, accurate interpolation of quantum process matrices over physical parameter space, and we apply our method to study the sensitivity of quantum applications at both the gate and circuit level. We then implement an extension of gate set tomography (GST) that provides a comprehensive view into the errors suffered by a quantum information processor. In its standard form, GST fits a general Markovian model to experimental data in terms of process matrices that are often difficult to interpret. Our extension to this method uses process matrices interpolated over physical parameters in the optimization loop of GST to directly estimate physical model parameters, providing a clear description of the errors in a quantum processor, while reducing the required number of GST sequences by orders of magnitude compared to its standard form.

This material was funded in part by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research's Early Career Research Program. SNL is managed and operated by NTESS LLC, a subsidiary of Honeywell International, Inc., for the U.S. DOE's NNSA under contract DE-NA0003525. The views expressed here do not necessarily represent the views of the DOE or the U.S. Government.