TY  - JOUR
AU  - Xu, Xuexin
AU  - Ansari, Mohammad
TI  - Z Z Freedom in Two-Qubit Gates
JO  - Physical review applied
VL  - 15
IS  - 6
SN  - 2331-7019
CY  - College Park, Md. [u.a.]
PB  - American Physical Society
M1  - FZJ-2021-04548
SP  - 064074
PY  - 2021
AB  - Superconducting qubits on a circuit exhibit an always-on state-dependent phase error. This error is due to sub-MHz parasitic interaction that repels computational levels from noncomputational ones. We study a general theory to evaluate the “static” repulsion between seemingly idle qubits as well as the “dynamical” repulsion between entangled qubits under microwave driving gate. By combining qubits of either the same or opposite anharmonicity signs we find the characteristics of static and dynamical ZZ freedoms. The latter universally eliminate the parasitic repulsion, leading us to mitigate high-fidelity gate operation. Our theory introduces the opportunities for making perfect entangled and unentangled states, which is extremely useful for quantum technology.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000670307200001
DO  - DOI:10.1103/PhysRevApplied.15.064074
UR  - https://juser.fz-juelich.de/record/902777
ER  -