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arXiv · 1203.4585

Ancilla models for quantum operations: For what unitaries does the ancilla state have to be physical?

Zhang Jiang·Marco Piani·Carlton M. Caves
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Abstract

Any evolution described by a completely positive trace-preserving linear map can be imagined as arising from the interaction of the evolving system with an initially uncorrelated ancilla. The interaction is given by a joint unitary operator, acting on the system and the ancilla. Here we study the properties such a unitary operator must have in order to force the choice of a physical- that is, positive-state for the ancilla if the end result is to be a physical-that is, completely positive-evolution of the system.

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Zhang Jiang, Marco Piani, Carlton M. Caves. 2012-11-27. Ancilla models for quantum operations: For what unitaries does the ancilla state have to be physical?. https://doi.org/10.1007/s11128-012-0500-x

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