Minimal and robust composite two-qubit gates with Ising-type interaction
Tsubasa Ichikawa, Utkan Güngördü, Masamitsu Bando, Yasushi Kondo, Mikio Nakahara · Physical Review A · 2013
We construct a minimal robust controlled-not gate with an Ising-type interaction by which elementary two-qubit gates are implemented. It is robust against inaccuracy of the coupling strength and the obtained quantum circuits are constructed with the minimal number ($N=3$) of elementary two-qubit gates and several one-qubit gates. It is noteworthy that all the robust circuits can be mapped to one-qubit circuits robust against a pulse length error. We also prove that a minimal robust swap gate cannot be constructed with $N=3$ but requires $N=6$ elementary two-qubit gates.