Cryptography Reference
In-Depth Information
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Figure 6.14
Circuit used to encode two logical qubits into four physical qubits, as
suggested by Gingrich et al. [5]. (Reprinted with permission from R.M. Gingrich,
P. Kok, H. Lee, F. Vatan, and J.P. Dowling, Phys. Rev. Lett., 91, 217901, 2003. Copyright
2003 by the American Physical Society.)
fiber that the probability of absorbing two or more photons in a distance
L
is
negligibly small. Alternatively, the optical fibers could be formed into a set
of loops to implement a quantum memory device, as described above, where
the error correction circuits would correct for the effects of photon loss and
extend the storage time [3,5].
Since the error correction circuit of Figure 6.15 does not correct for other
types of errors, it will also be necessary to minimize the failure rate of the
CNOT gates by using a sufficiently large number of ancilla photons [2] or by
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Figure 6.15
A circuit that can be used to correct for photon loss based on the four-
qubit encoding of Figure 6.14, as proposed by Gingrich et al. [5]. (Reprinted with
permission from R.M. Gingrich, P. Kok, H. Lee, F. Vatan, and J.P. Dowling, Phys. Rev.
Lett., 91, 217901, 2003. Copyright 2003 by the American Physical Society.)
