Förster Resonances and Rydberg-Blockade CPhase Gate in a Dual-Species Atom-Array

Neutral atoms are a compelling candidate for quantum information science. Trapped in reconfigurable tweezer arrays, qubits can be encoded in long-lived electronic ground states. Single-qubit gates are achieved using microwave or Raman transitions, while 2-qubit gates can be engineered via Rydberg-blockade. A challenge in this platform is combining coherent operations with programmable connectivity and non-destructive measurements. Recently, we showed that the additional tools offered by a dual-species array of ⁸⁷Rb and ¹³³Cs enable crosstalk-free measurements and auxiliary qubit-assisted protocols [1]. In this talk I will present our recent efforts at demonstrating the first dual-element 2-qubit gate. We achieve interaction strengths of tens of MHz via an electrically-tuned Förster resonance, and use this to generate inter-element entanglement. This resonance also leads to the emergence of multiple interaction energy scales in the system. I will describe how the tunable asymmetry between resonant inter-species dipole-dipole interactions and intra-species van der Waals' interactions naturally extends to multi-qubit gate schemes.

[1] Singh et. al., Science 380, 1265 (2023)