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Exact two-qubit universal quantum circuit

Jun Zhang·Jiri Vala·Shankar Sastry·K. Birgitta Whaley
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Abstract

We provide an analytic way to implement any arbitrary two-qubit unitary operation, given an entangling two-qubit gate together with local gates. This is shown to provide explicit construction of a universal quantum circuit that exactly simulates arbitrary two-qubit operations in SU(4). Each block in this circuit is given in a closed form solution. We also provide a uniform upper bound of the applications of the given entangling gates, and find that exactly half of all the Controlled-Unitary gates satisfy the same upper bound as the CNOT gate. These results allow for the efficient implementation of operations in SU(4) required for both quantum computation and quantum simulation.

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Jun Zhang, Jiri Vala, Shankar Sastry, K. Birgitta Whaley. 2003-05-15. Exact two-qubit universal quantum circuit. https://doi.org/10.1103/physrevlett.91.027903

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