Typical qubit gate operations are binary, involving operations with up to just two qubits. While this can be universal, it is more efficient for almost all quantum circuits to directly entangle qubits with N-body interactions. With trapped ions, gates are typically realized by applying optical state-dependent displacements to the ions. By instead using state-dependent squeezing forces, the workhorse quantum gate between pairs of trapped ions is extended to an N-qubit gate. This is an important shortcut for most quantum circuits such as quantum error-correction encoding and quantum optimization circuits, while also providing direct N-body interactions for quantum simulations of many-body quantum systems.
- “Demonstration of three- and four-body interactions between trapped-ion spins,” Or Katz, Lei Feng, Andrew Risinger, Christopher Monroe, Marko Cetina, Nature Physics 19, 1452 (2023); arXiv:2209.05691.
- “Programmable N-body interactions with trapped ions,” O. Katz, M. Cetina, and C. Monroe, Phys. Rev. X Quantum 4, 030311 (2023); arXiv:2207.10550.
- “N-body interactions between trapped ion qubits via spin-dependent squeezing,” O. Katz, M. Cetina, and C. Monroe, Phys. Rev. Lett. 129, 063603 (2022).