Optimal two-qubit quantum circuits using exchange interactions
نویسندگان
چکیده
We give the optimal decomposition of a universal two-qubit circuit using Heisenberg exchange interactions and single qubit rotations. Tuning the strength and duration of the Heisenberg exchange allows one to implement SWAP gates. Our optimal circuit is constructed from only three SWAP gates and six single qubit gates. We show that three SWAP gates are not only sufficient, but necessary. Since six single-qubit gates are already known to be necessary, our implementation is optimal in gate count.
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