Engineering long-range and multi-body interactions via global kinetic constraints

TL;DR

This paper proposes a cold atom-based scheme to realize long-range and multi-body interactions using global kinetic constraints, enabling efficient quantum gates and entangled state preparation.

Contribution

It introduces a novel method to induce global kinetic constraints in a Bose-Hubbard system, facilitating implementation of complex quantum interactions and gates.

Findings

Global kinetic constraints can be induced via periodic driving in Bose-Hubbard systems.

The scheme enables direct implementation of multi-qubit gates like the Toffoli gate.

Efficient preparation of entangled many-body states is demonstrated.

Abstract

Long-range and multi-body interactions are crucial for quantum simulation and quantum computation. Yet, their practical realization using elementary pairwise interactions remains an outstanding challenge. We propose an experimental scheme based on the Bose-Hubbard system with a periodic driving of the on-site energy and global-range density-density interactions, a setup readily implementable via cold atoms in optical lattices with cavity-mediated interactions. Optimally chosen driving parameters can induce global kinetic constraints, where tunneling rates are selectively suppressed depending on the particle number imbalance between all even and odd sites. This mechanism, together with the flexible tunability of local tunneling rates, provides efficient implementation schemes of a family of global controlled gates for quantum computation. We illustrate this scheme for the $N$-qubit Toffoli gate, circumventing the need for a two-body gate decomposition, and elaborate on the efficient preparation of entangled many-body states.