Quantum Process Tomography with Digital Twins of Error Matrices
Journal article, 2025
Accurate and robust quantum process tomography (QPT) is crucial for verifying quantum gates and diagnosing implementation faults in experiments aimed at building universal quantum computers. However, the reliability of QPT protocols is often compromised by faulty probes, particularly state preparation and measurement (SPAM) errors, which introduce fundamental inconsistencies in traditional QPT algorithms. We propose and investigate enhanced QPT for multiqubit systems by integrating the error matrix in a digital twin of the identity process matrix, enabling statistical refinement of SPAM error learning and improving QPT precision. Through numerical simulations, we demonstrate that our approach enables highly accurate and faithful process characterization. We further validate our method experimentally in superconducting quantum processors, achieving at least an order-of-magnitude fidelity improvement over standard QPT. Our results provide a practical and precise method for assessing quantum gate fidelity and enhancing QPT on a given hardware.
Author
Tangyou Huang
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Aalto University
Akshay Gaikwad
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Ilya Moskalenko
Aalto University
Anuj Aggarwal
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Tahereh Abad
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Marko Kuzmanović
Aalto University
Yu Han Chang
Aalto University
Ognjen Stanisavljević
Aalto University
Emil Hogedal
Quantum Technology PhD Students
Christopher Warren
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Irshad Ahmad
Quantum Technology Postdocs
Janka Biznárová
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Amr Osman
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Mamta Mamta
Quantum Technology Postdocs
Marcus Rommel
Chalmers, Microtechnology and Nanoscience (MC2), Nanofabrication Laboratory
Anita Fadavi Roudsari
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Andreas Nylander
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Liangyu Chen
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Jonas Bylander
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Gheorghe Sorin Paraoanu
Aalto University
Anton Frisk Kockum
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
Giovanna Sammarco Tancredi
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 135 23 230601Quantum simulation and communication with giant atoms
Swedish Foundation for Strategic Research (SSF) (FFL21-0279), 2022-08-01 -- 2027-12-31.
Wallenberg Centre for Quantum Technology (WACQT)
Knut and Alice Wallenberg Foundation (KAW 2017.0449, KAW2021.0009, KAW2022.0006), 2018-01-01 -- 2030-03-31.
Subject Categories (SSIF 2025)
Computer Sciences
Infrastructure
Myfab (incl. Nanofabrication Laboratory)
DOI
10.1103/dpgy-rtxr