Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 211-232 |
| Seitenumfang | 22 |
| Fachzeitschrift | J. Mod. Opt. |
| Jahrgang | 47 |
| Ausgabenummer | 2-3 |
| Publikationsstatus | Veröffentlicht - 2000 |
Abstract
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in: J. Mod. Opt., Jahrgang 47, Nr. 2-3, 2000, S. 211-232.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Universal-NOT gate
AU - Buzek, V.
AU - Hillery, M.
AU - Werner, R. F.
N1 - Physics of quantum information
PY - 2000
Y1 - 2000
N2 - It is not a problem to complement a classical bit, i.e. to change the value of a bit, a 0 to a 1 and vice versa. This is accomplished by a NOT gate. Complementing a qubit in an unknown state, however, is another matter. We show that this operation cannot be done perfectly. We define the Universal-NOT (U-NOT) gate which out of N identically prepared pure input qubits generates M output qubits in a state which is as close as possible to the perfect complement. This gate can be realized by classical estimation and subsequent re-preparation of complements of the estimated state. Its fidelity is therefore equal to the fidelity F= (N+1)/(N+2) of optimal estimation, and does not depend on the required number of outputs. We also show that when some additional a priori information about the state of input qubit is available, than the fidelity of the quantum NOT gate can be much better than the fidelity of estimation.
AB - It is not a problem to complement a classical bit, i.e. to change the value of a bit, a 0 to a 1 and vice versa. This is accomplished by a NOT gate. Complementing a qubit in an unknown state, however, is another matter. We show that this operation cannot be done perfectly. We define the Universal-NOT (U-NOT) gate which out of N identically prepared pure input qubits generates M output qubits in a state which is as close as possible to the perfect complement. This gate can be realized by classical estimation and subsequent re-preparation of complements of the estimated state. Its fidelity is therefore equal to the fidelity F= (N+1)/(N+2) of optimal estimation, and does not depend on the required number of outputs. We also show that when some additional a priori information about the state of input qubit is available, than the fidelity of the quantum NOT gate can be much better than the fidelity of estimation.
M3 - Article
VL - 47
SP - 211
EP - 232
JO - J. Mod. Opt.
JF - J. Mod. Opt.
IS - 2-3
ER -