A Field Guide to many-body entanglement: expanding the NP-QIS toolbox

Entanglement is a resource that allows quantum systems to contain exponentially more information than the sum of their parts. Such correlations are celebrated for their role in sourcing quantum advantages toward complex simulations of many-body dynamics or precision sensing below the standard quantum limit. Further complementing technological applications, deciphering the entanglement inherent in fields, organizing nuclear structure, and active in coherent scattering has begun to reveal new insights into nuclear physics phenomena from emergent symmetries to thermalization to phase transitions.

Due to nuanced interplay between classical and quantum correlations, entropies are not sufficient for quantifying entanglement within mixed quantum states, e.g., in noisy environments or partial observations by arrays of local detectors. Beyond digging deeper into the QIS toolbox, the elaborate quantum systems of nuclear physics have begun to guide the creation of new techniques for calculating otherwise-intractable properties of natural quantum information. Focusing on the spacelike entanglement inherent in simple field vacuum states, we will discuss this interplay to see that the entanglement observable by pairs of local detectors as a function of their separation is exponentially less than the corresponding spatial decay of two-point correlation functions. Inspiring applications in quantum codesign, this path continues to enhance the role and understanding of how Nature stores and processes entangled information.