Overcoming leakage in scalable quantum error correction
Abstract
Leakage of quantum information out of computational states into higher energy states represents a major challenge in the pursuit of quantum error correction (QEC). In a QEC circuit, leakage builds over time and spreads through multi-qubit interactions. This leads to correlated errors that degrade the exponential suppression of logical error with scale, challenging the feasibility of QEC as a path towards fault-tolerant quantum computation. Here, we demonstrate the execution of a distance-3 surface code and distance-21 bit-flip code on a Sycamore quantum processor where leakage is removed from all qubits in each cycle. This shortens the lifetime of leakage and curtails its ability to spread and induce correlated errors. We report a ten-fold reduction in steady-state leakage population on the data qubits encoding the logical state and an average leakage population of less than throughout the entire device. The leakage removal process itself efficiently returns leakage population back to the computational basis, and adding it to a code circuit prevents leakage from inducing correlated error across cycles, restoring a fundamental assumption of QEC. With this demonstration that leakage can be contained, we resolve a key challenge for practical QEC at scale.
Cite
@article{arxiv.2211.04728,
title = {Overcoming leakage in scalable quantum error correction},
author = {Kevin C. Miao and Matt McEwen and Juan Atalaya and Dvir Kafri and Leonid P. Pryadko and Andreas Bengtsson and Alex Opremcak and Kevin J. Satzinger and Zijun Chen and Paul V. Klimov and Chris Quintana and Rajeev Acharya and Kyle Anderson and Markus Ansmann and Frank Arute and Kunal Arya and Abraham Asfaw and Joseph C. Bardin and Alexandre Bourassa and Jenna Bovaird and Leon Brill and Bob B. Buckley and David A. Buell and Tim Burger and Brian Burkett and Nicholas Bushnell and Juan Campero and Ben Chiaro and Roberto Collins and Paul Conner and Alexander L. Crook and Ben Curtin and Dripto M. Debroy and Sean Demura and Andrew Dunsworth and Catherine Erickson and Reza Fatemi and Vinicius S. Ferreira and Leslie Flores Burgos and Ebrahim Forati and Austin G. Fowler and Brooks Foxen and Gonzalo Garcia and William Giang and Craig Gidney and Marissa Giustina and Raja Gosula and Alejandro Grajales Dau and Jonathan A. Gross and Michael C. Hamilton and Sean D. Harrington and Paula Heu and Jeremy Hilton and Markus R. Hoffmann and Sabrina Hong and Trent Huang and Ashley Huff and Justin Iveland and Evan Jeffrey and Zhang Jiang and Cody Jones and Julian Kelly and Seon Kim and Fedor Kostritsa and John Mark Kreikebaum and David Landhuis and Pavel Laptev and Lily Laws and Kenny Lee and Brian J. Lester and Alexander T. Lill and Wayne Liu and Aditya Locharla and Erik Lucero and Steven Martin and Anthony Megrant and Xiao Mi and Shirin Montazeri and Alexis Morvan and Ofer Naaman and Matthew Neeley and Charles Neill and Ani Nersisyan and Michael Newman and Jiun How Ng and Anthony Nguyen and Murray Nguyen and Rebecca Potter and Charles Rocque and Pedram Roushan and Kannan Sankaragomathi and Christopher Schuster and Michael J. Shearn and Aaron Shorter and Noah Shutty and Vladimir Shvarts and Jindra Skruzny and W. Clarke Smith and George Sterling and Marco Szalay and Douglas Thor and Alfredo Torres and Theodore White and Bryan W. K. Woo and Z. Jamie Yao and Ping Yeh and Juhwan Yoo and Grayson Young and Adam Zalcman and Ningfeng Zhu and Nicholas Zobrist and Hartmut Neven and Vadim Smelyanskiy and Andre Petukhov and Alexander N. Korotkov and Daniel Sank and Yu Chen},
journal= {arXiv preprint arXiv:2211.04728},
year = {2024}
}
Comments
Main text: 7 pages, 5 figures