Simulating highly nonlocal Hamiltonians with less nonlocal Hamiltonians

Understand

The need for Hamiltonians with many-body interactions arises in various applications of quantum computing.

• However, interactions beyond two-body are difficult to realize experimentally.
• Perturbative gadgets were introduced to obtain arbitrary many-body effective interactions using Hamiltonians with two-body interactions only.
• Although valid for arbitrary $k$-body interactions, their use is limited to small $k$ because the strength of interaction is $k$'th order in perturbation theory.