Details
| Original language | English |
|---|---|
| Pages (from-to) | 1-26 |
| Number of pages | 26 |
| Journal | Ann. Inst. H. Poincaré Phys. Théor. |
| Volume | 2 |
| Issue number | 1 |
| Publication status | Published - 2001 |
Abstract
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In: Ann. Inst. H. Poincaré Phys. Théor., Vol. 2, No. 1, 2001, p. 1-26.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The rate of optimal purification procedures
AU - Keyl, M.
AU - Werner, R. F.
PY - 2001
Y1 - 2001
N2 - Purification is a process in which decoherence is partially reversed by using several input systems which have been subject to the same noise. The purity of the outputs generally increases with the number of input systems, and decreases with the number of required output systems. We construct the optimal quantum operations for this task, and discuss their asymptotic behaviour as the number of inputs goes to infinity. The rate at which output systems may be generated. depends crucially on the type of purity requirement. If one tests the purity of the output systems one at a time, the rate is infinite : this fidelity may be made to approach 1, while at the same time the number of outputs goes to infinity arbitrarily fast. On the other hand, if one also requires the correlations between outputs to decrease, the rate is zero: if fidelity with the pure product state is to go to 1, the number of outputs per input goes to zero. However, if only a fidelity close to 1 is required, the optimal purifier achieves a positive rate, which we compute.
AB - Purification is a process in which decoherence is partially reversed by using several input systems which have been subject to the same noise. The purity of the outputs generally increases with the number of input systems, and decreases with the number of required output systems. We construct the optimal quantum operations for this task, and discuss their asymptotic behaviour as the number of inputs goes to infinity. The rate at which output systems may be generated. depends crucially on the type of purity requirement. If one tests the purity of the output systems one at a time, the rate is infinite : this fidelity may be made to approach 1, while at the same time the number of outputs goes to infinity arbitrarily fast. On the other hand, if one also requires the correlations between outputs to decrease, the rate is zero: if fidelity with the pure product state is to go to 1, the number of outputs per input goes to zero. However, if only a fidelity close to 1 is required, the optimal purifier achieves a positive rate, which we compute.
U2 - 10.1007/PL00001027
DO - 10.1007/PL00001027
M3 - Article
VL - 2
SP - 1
EP - 26
JO - Ann. Inst. H. Poincaré Phys. Théor.
JF - Ann. Inst. H. Poincaré Phys. Théor.
IS - 1
ER -