PreprintCC BY 4.0arXiv
Impossible to conjugate or reflect an unknown quantum state via a unitary evolution
Abstract
The no-cloning theorem, the no-deleting theorem, and other no-go theorems play a crucial role in quantum mechanics and quantum information. In this paper, we show that it is impossible to conjugate or reflect an unknown quantum state or conjugate or reflect the bit-flip (the phase-flip) of an unknown state via a universally unitary evolution. We also indicate that the partial conjugating operations are not anti-unitary and it is impossible to universally partially conjugate an unknown state via a unitary evolution. We compute the fidelities of the optimal physical approximations to conjugating and conjugating the bit-flip and phase-flip operations.
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BibTeX
@misc{li2026impossible,
title = {{Impossible to conjugate or reflect an unknown quantum state via a unitary evolution}},
author = {Dafa Li},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.11536},
eprint = {2609.11536},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.11536},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Impossible to conjugate or reflect an unknown quantum state via a unitary evolution
AU - Dafa Li
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2609.11536
UR - https://arxiv.org/abs/2609.11536
AB - The no-cloning theorem, the no-deleting theorem, and other no-go theorems play a crucial role in quantum mechanics and quantum information. In this paper, we show that it is impossible to conjugate or reflect an unknown quantum state or conjugate or reflect the bit-flip (the phase-flip) of an unknown state via a universally unitary evolution. We also indicate that the partial conjugating operations are not anti-unitary and it is impossible to universally partially conjugate an unknown state via a unitary evolution. We compute the fidelities of the optimal physical approximations to conjugating and conjugating the bit-flip and phase-flip operations.
ER -