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Equation 19 · Part 1 · Error Correction Is the Whole Problem in Quantum Computing

Symbol p_th

pthp_{\mathrm{th}}
pthp_{\mathrm{th}}

What this part means

ptp_th is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

ptp_th is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

The threshold theorem is the reason the field exists. Stated informally: if the physical error rate per operation is below some constant pthp_{\mathrm{th}} determined by the code, the noise model and the fault-tolerant circuit construction, then an arbitrarily long quantum computation can be performed with arbitrarily small error, at an overhead that grows only polylogarithmically in the size of the computation. Knill, Laflamme and Zurek established resilient computation under a constant error rate [ 5 ] , and Aharonov and Ben-Or gave the constant-error-rate construction in a form that has become the standard citation [ 6 ] .

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Sources cited in the surrounding passage

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