On the classical character of control fields in quantum information processing
Keyword(s):
Control fields in quantum information processing are almost by definition assumed to be classical. In reality, however, when such a field is used to manipulate the quantum state of qubits, the qubits always become slightly entangled with the field. For quantum information processing this is an undesirable property, as it precludes perfect quantum computing and quantum communication. Here we consider the interaction of atomic qubits with laser fields and quantify atom-field entanglement in various cases of interest. We find that the entanglement decreases with the average number of photons \bar{n} in a laser beam as $E\propto\log_2 \bar{n}/\bar{n}$ for $\bar{n}\rightarrow\infty$.
2001 ◽
Vol 15
(27)
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pp. 1259-1264
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2018 ◽
Vol 18
(13&14)
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pp. 1125-1142
2009 ◽
Vol 07
(06)
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pp. 1255-1267
2010 ◽
Vol 50
(4)
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pp. 1305-1318
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