dorsal/arxiv
View SchemaUnital quantum operators on the Bloch ball and Bloch region
| Authors | P. S. Bourdon, H. T. Williams |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0308089 |
| URL | https://arxiv.org/abs/quant-ph/0308089 |
| DOI | 10.1103/PhysRevA.69.022314 |
Abstract
For one qubit systems, we present a short, elementary argument characterizing unital quantum operators in terms of their action on Bloch vectors. We then show how our approach generalizes to multi-qubit systems, obtaining inequalities that govern when a ``diagonal'' superoperator on the Bloch region is a quantum operator. These inequalities are the n-qubit analogue of the Algoet-Fujiwara conditions. Our work is facilitated by an analysis of operator-sum decompositions in which negative summands are allowed.
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"abstract": "For one qubit systems, we present a short, elementary argument characterizing\nunital quantum operators in terms of their action on Bloch vectors. We then\nshow how our approach generalizes to multi-qubit systems, obtaining\ninequalities that govern when a ``diagonal\u0027\u0027 superoperator on the Bloch region\nis a quantum operator. These inequalities are the n-qubit analogue of the\nAlgoet-Fujiwara conditions. Our work is facilitated by an analysis of\noperator-sum decompositions in which negative summands are allowed.",
"arxiv_id": "quant-ph/0308089",
"authors": [
"P. S. Bourdon",
"H. T. Williams"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.69.022314",
"title": "Unital quantum operators on the Bloch ball and Bloch region",
"url": "https://arxiv.org/abs/quant-ph/0308089"
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