Tunable spin-spin interactions and entanglement of ions in separate wells

TL;DR

This paper demonstrates a method for tunably controlling spin-spin interactions and entanglement between ions in separate wells, advancing scalable quantum simulation architectures with potential applications in condensed matter physics.

Contribution

It introduces a scheme for deterministic tuning of Coulomb interactions between ions in separate wells, enabling scalable and flexible quantum simulation setups.

Findings

Achieved 0.82 fidelity in entangling ion states.

Demonstrated independent control of local wells and interactions.

Proposed extension to 2D ion networks for complex simulations.

Abstract

Quantum simulation - the use of one quantum system to simulate a less controllable one - may provide an understanding of the many quantum systems which cannot be modeled using classical computers. Impressive progress on control and manipulation has been achieved for various quantum systems, but one of the remaining challenges is the implementation of scalable devices. In this regard, individual ions trapped in separate tunable potential wells are promising. Here we implement the basic features of this approach and demonstrate deterministic tuning of the Coulomb interaction between two ions, independently controlling their local wells. The scheme is suitable for emulating a range of spin-spin interactions, but to characterize the performance of our setup we select one that entangles the internal states of the two ions with 0.82(1) fidelity. Extension of this building-block to a 2D-network, which ion-trap micro-fabrication processes enable, may provide a new quantum simulator architecture with broad flexibility in designing and scaling the arrangement of ions and their mutual interactions. To perform useful quantum simulations, including those of intriguing condensed-matter phenomena such as the fractional quantum Hall effect, an array of tens of ions might be sufficient.