2008/02/08 by Caleb J O'Loan, O'Loan, Caleb J
Engineering · Physics and Astronomy · #FOS: Physical sciences #Fault Detection and Control Systems #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.0802.1181
4 pages
arxiv created 2008/02/08 · openalex publication_date 2008/02/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the simultaneous estimation of n not necessarily identical unitary channels using multi-partite entanglement. We examine whether it is possible for the rate at which the mean square error decreases to be greater than that using the channels individually. For a reasonably general situation, in which there is no functional dependence between the channels, we show that this is not possible. We look at a case in which the channels are not necessarily identical but depend on a common variable. In this case, the mean square error decreases more rapidly using multi-partite entanglement.