Generation of multi-qubit entanglement in a superconducting quantum circuit by parallelized parity measurements
Stefano Poletto, Diego Ristè, Meng-Zi Huang, Alessandro Bruno, Visa Vesterinen, O.-P. Saira, L. DiCarlo · Bulletin of the American Physical Society · 2015
ve qubit superconducting processor. Two-qubit Bell states and three-qubit GHZ-type states are generated by single and double two-qubit parity measurements on superposition states, respectively, and characterized by both witnessing and state tomography. The protocol for generation of GHZ-type states can be used as the encoding step in the three-qubit bit-ip quantum error correction code, and made deterministic by digital feedback control. We assess its performance by state tomography of the six encoded cardinal states, and compare to the traditional method of encoding by gates.