Spectral Quantum Tomography
Quantum Physics
2020-02-19 v2
Abstract
We introduce spectral quantum tomography, a simple method to extract the eigenvalues of a noisy few-qubit gate, represented by a trace-preserving superoperator, in a SPAM-resistant fashion, using low resources in terms of gate sequence length. The eigenvalues provide detailed gate information, supplementary to known gate-quality measures such as the gate fidelity, and can be used as a gate diagnostic tool. We apply our method to one- and two-qubit gates on two different superconducting systems available in the cloud, namely the QuTech Quantum Infinity and the IBM Quantum Experience. We discuss how cross-talk, leakage and non-Markovian errors affect the eigenvalue data.
Cite
@article{arxiv.1904.00177,
title = {Spectral Quantum Tomography},
author = {Jonas Helsen and Francesco Battistel and Barbara M. Terhal},
journal= {arXiv preprint arXiv:1904.00177},
year = {2020}
}
Comments
13 pages, 6 figures v2: various minor changes, close to accepted version