Fig. 1
From: Realisation of high-fidelity nonadiabatic CZ gates with superconducting qubits
Nonadiabatic CZ gate design. a Principle of nonadiabatic CZ gate. |11〉 is moved rapidly to the interaction point and interacted with |20〉 for period of time and then moved back to the idle point. b Detuning pulse. The ideal, infinite-bandwidth pulse (green) moves instantaneously the interaction point. The realistic, 300 MHz-bandwidth pulse (red) has added edges on either side. The ideal (realistic) pulse takes 34 ns (40 ns) in theory. c Swap space. The green (red) circle shows the evolution resulting from the ideal (realistic) control pulse. The small green and red diamonds in x–z plane are the eigenstates during each of these evolutions. After the operation, the |11〉 has gained a phase of π relative to the other states. d State population in the eigenstate during the pulse. A large part of the population can be seen exiting and then re-entering the eigenstate
