Resonant-interaction-induced Rydberg antiblockade and its applications

Abstract

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.

Effective Rabi dynamics of Rydberg atoms and robust high-fidelity quantum gates with a resonant amplitude-modulation field

“…The deviation range of d keeping F > 0.99 is less than 2 nm. In fact, the extreme sensitivity to errors in the interatomic distance as well as the RRI strength is a common issue for the RAB gate schemes [13][14][15][16]. The shortcomings itemized above of implementing the CZ gate can be overcome by breaking the RAB, as shown in the next section.…”

“…Alternatively, we here mainly focus on a controlled-Z (CZ) gate formed straightforwardly through a single Rabi cycle. Similar to the existing RAB schemes [1,9,[13][14][15][16][17], the implementation of this CZ gate may also encounter with the obstacles of the RAB gates.…”

Landau-Zener transitions and adiabatic impulse approximation in an array of two Rydberg atoms with time-dependent detuning

“…We discussed in detail the validity of AIA in describing the dynamics for both linear and periodic variation of detuning. Interestingly, AIA reveals detailed information about the phases developed during the dynamics, which can be very useful for applications such as coherent control of quantum states, implementing quantum (phase) gates [66,67], and atom-interferometry [31].…”

“…Periodic modulation in detuning can suppress Rabi couplings, which can lead to selective (state-dependent) population trapping. Not only that, periodic driving in Rydberg gases provides us insights into fundamental problems, but also finds applications in developing robust quantum gates [66,67]. To implement periodic driving in a Rydberg chain, one can modulate the light field which couples the ground to the Rydberg state.…”

Population trapping in a pair of periodically driven Rydberg atoms

“…For two atoms, it has been predicted that through modulation induced resonances, one can engineer the parameter space for both Rydberg-blockade and anti-blockade [44][45][46]. The latter is proposed to have applications in implementing robust quantum gates [46][47][48] and accelerating the formation of dissipative entangled steady states [49]. To realize periodic driving in a Rydberg chain, either one can modulate the light field that couples the ground to the Rydberg state or applying additional radio-frequency fields.…”