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Two-qubit Projective Measurements are Universal for Quantum Computation

D. W. Leung
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Abstract

Nielsen [quant-ph/0108020] showed that universal quantum computation is possible given quantum memory and the ability to perform projective measurements on up to 4-qubits. We describe an improved method that requires only 2-qubit measurements, which are both sufficient and necessary. We present a method to partially collapse the $C_k$-hierarchy in the indirect construction of unitary gates [Gottesman and Chuang, Nature, {\bf 402} 309 (1999)], and apply the method to find discrete universal sets of 2-qubit measurements.

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D. W. Leung. 2002-04-09. Two-qubit Projective Measurements are Universal for Quantum Computation. https://arxiv.org/abs/quant-ph/0111122

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