Exceptional Points and Optimized Encoding in Qubit Stabilizer Codes
Abstract
Continuous blind stabilizer measurements turn stabilizer codes into a Liouvillian spectral problem in which Hamiltonian terms compete with dissipative error channels. We show that this competition generically enables Liouvillian exceptional points, whose occurrence at weak error rates is constrained by the code distance. Exceptional points are detrimental in this regime of error correction as they maximize the decay rate of encoded coherences. We then optimize the encoding of the logical qubit using the eigenmodes of the Lindblad operator. This phase-optimized encoding cancels the linear short-time decay of logical qubit coherences. We apply this encoding to the [[5,1,3]] code and demonstrate that it outperforms naive encoding methods near the exceptional point, improves the fidelity of a logical π rotation and remains effective in the presence of additional weak error channels.
Related
- Noise redistribution by stabilizer codes: an organizing view of concatenated three-qubit codes
- Distillation of N-Qubit Stabilizer States on a Star Network Topology
- Rank-one loss maximizes the spectral response strength of passive full-order exceptional points
- Exceptional points in topological spoof surface plasmon polaritons for index sensing applications
- Liouvillian exceptional-point-induced phase transition in a single Kerr-cat qubit
BibTeX
@misc{rottstaedt2026exceptional,
title = {{Exceptional Points and Optimized Encoding in Qubit Stabilizer Codes}},
author = {Yves Rottstaedt and Andrei I. Pavlovm Alexander Shnirman and Yuval Gefen and Bernd Rosenow},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.03469},
eprint = {2611.03469},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.03469},
}
RIS
TY - UNPB
TI - Exceptional Points and Optimized Encoding in Qubit Stabilizer Codes
AU - Yves Rottstaedt
AU - Andrei I. Pavlovm Alexander Shnirman
AU - Yuval Gefen
AU - Bernd Rosenow
PY - 2026
DA - 2026/11/02
PB - arXiv
DO - 10.48550/arxiv.2611.03469
UR - https://arxiv.org/abs/2611.03469
AB - Continuous blind stabilizer measurements turn stabilizer codes into a Liouvillian spectral problem in which Hamiltonian terms compete with dissipative error channels. We show that this competition generically enables Liouvillian exceptional points, whose occurrence at weak error rates is constrained by the code distance. Exceptional points are detrimental in this regime of error correction as they maximize the decay rate of encoded coherences. We then optimize the encoding of the logical qubit using the eigenmodes of the Lindblad operator. This phase-optimized encoding cancels the linear short-time decay of logical qubit coherences. We apply this encoding to the [[5,1,3]] code and demonstrate that it outperforms naive encoding methods near the exceptional point, improves the fidelity of a logical π rotation and remains effective in the presence of additional weak error channels.
ER -