Quantum computing with atomic qubits and Rydberg interactions: progress and challenges

Abstract

We present a review of quantum computation with neutral atom qubits. After an overview of architectural options and approaches to preparing large qubit arrays we examine Rydberg mediated gate protocols and fidelity for two-and multi-qubit interactions. Quantum simulation and Rydberg dressing are alternatives to circuit based quantum computing for exploring many body quantum dynamics. We review the properties of the dressing interaction and provide a quantitative figure of merit for the complexity of the coherent dynamics that can be accessed with dressing. We conclude with a summary of the current status and an outlook for future progress.

Annulled van der Waals interaction and fast Rydberg quantum gates

“…We find that E L drops from 3.0 × 10 −3 to 1.5 × 10 −3 when U increases from 3.5 mK, as realized in [47], to 60 mK. Since attaining U of order a few times 10 mK is feasible for an optical trap [22], atomic separation errors may be suppressed.…”

“…Setting the trap depth U equal to a few times of 10 mK is feasible for an optical trap [22]. Moreover, the fact that the necessary conditions to (i) cool neutral atoms to their motional ground states [46] and (ii) load neutral atoms efficiently to optical tweezer lattice of a small lattice constant [47] were already demonstrated in experiments.…”

“…The Rydberg blockade quantum gate time is limited by the effective Rabi frequency, Ω, of the fields that rotate the qubit basis states [22]. The blockade effect is caused by the vdWI shifting the two-atom Rydberg state by a characteristic frequency B.…”

Dissipative stabilization of quantum-feedback-based multipartite entanglement with Rydberg atoms

“…In this paper, we propose an efficient scheme for stabilization of quantum-feedback-based entanglement with Rydberg atoms [33][34][35][36][37][38][39]. The advantage for adopting Rydberg atoms as qubits is twofold: On the one hand, an excited atom can cause sufficiently large energy shifts of Rydberg states in its neighboring atoms, thus the whole system is blockaded into a single excitation subspace at most.…”

Control of rubidium low-lying Rydberg states with trichromatic femtosecond π pulses for ultrafast quantum information processing

“…Selective excitation and manipulation of Rydberg states plays a crucial role in quantum information processing, a field of rapid theoretical and experimental progress with a large number of proposals for quantum information processors being investigated [1,2]. A central issue is the design of fast quantum gates, with recent proposals using neutral atoms and molecules that allow gate operation times set by the time scale of the laser excitation [3][4][5].…”