General theory of measurement with two copies of a quantum state
| dc.creator | Bendersky, Ariel | |
| dc.creator | Paz, Juan Pablo | |
| dc.creator | Cunha, Marcelo Terra | |
| dc.date | 2009-04-22 | |
| dc.date.accessioned | 2026-07-07T13:07:50Z | |
| dc.date.available | 2026-07-07T13:07:50Z | |
| dc.description | We analyze the possible results of the most general measurement on two copies of a quantum state. We show that $μ$ can label a set of outcomes of such measurement if and only if there is a family of completely co--positive (ccP) maps $C_μ$ such that the probability of occurrence $Prob(μ)$ is the fidelity of the map $C_μ$, i.e. $Prob(μ)= Tr(ρC_μ(ρ))$ which must add up to the fully depolarizing map. This implies that a POVM on two copies induces a measure on the set of ccP maps (i.e., a ccPMVM). We present examples of ccPMVM's and discuss their tomographic applications showing that two copies of a state provide an exponential improvement in the efficiency of quantum state tomography. This enables the existence of an efficient universal detector. | |
| dc.description | 4 pages, 1 figure | |
| dc.identifier | https://arxiv.org/abs/0904.3576 | |
| dc.identifier | http://arxiv.org/abs/0904.3576 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/228220 | |
| dc.subject | Quantum Physics | |
| dc.title | General theory of measurement with two copies of a quantum state | |
| dc.type | text |