  Different from the conventional Rydberg antiblockade (RAB) regime that either
requires weak Rydberg-Rydberg interaction (RRI), or compensates Rydberg-Rydberg
interaction (RRI)-induced energy shift by introducing dispersive interactions,
we show that RAB regime can be achieved by resonantly driving the transitions
between ground state and Rydberg state under strong RRI. The Rabi frequencies
are of small amplitude and time-dependent harmonic oscillation, which plays a
critical role for the presented RAB. The proposed unconventional RAB regime is
used to construct high-fidelity controlled-Z (CZ) gate and controlled-not
(CNOT) gate in one step. Each atom requires single external driving. And the
atomic addressability is not required for the presented unconventional RAB,
which would simplify experimental complexity and reduce resource consumption.
