Bonn 2025 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

QI: Fachverband Quanteninformation

QI 36: Poster – Quantum Information (joint session QI/Q)

QI 36.19: Poster

Donnerstag, 13. März 2025, 17:00–19:00, Tent

Multi-Pass Quantum Process Tomography — •Stancho Stanchev and Nikolay Vitanov — Center for Quantum Technologies, Faculty of Physics, Sofia University, James Bourchier 5 blvd., 1164 Sofia, Bulgaria

We introduce a method to enhance the precision and accuracy of Quantum Process Tomography (QPT) by mitigating errors caused by state preparation and measurement (SPAM), readout, and shot noise. Instead of performing QPT on a single gate, we propose applying QPT to a sequence of multiple applications of the same gate. The method involves the measurement of the Pauli transfer matrix (PTM) by standard QPT of the multipass process, and then deduce the single-process PTM by two alternative approaches: an iterative approach which in theory delivers the exact result for small errors, and a linearized approach based on solving the Sylvester equation. We apply the method to CNOT gate tomography, as well as to evaluate the quality of single-qubit composite gates, constructed by composite pulses and compare them to pre-existing gates. We assess the method's performance through simulations on IBM Quantum, using IBM Simulator and real quantum processors.

Keywords: Quantum Process Tomography; Accuracy and Precision; Quantum channels; Process Fidelity; Diamond norm