One of the greatest challenges in physics is to understand how collective, macroscopic behaviors, such as phase transitions, emerge from the microscopic dynamics of the constituents of a system. A pivotal approach to tackle such many-body problems is offered by quantum field theory (QFT), which plays a central role in describing, for instance, superconductivity and the quantum Hall effect. QFT makes a number of problems solvable by describing a system in terms of fields distributed in space and time, while neglecting many of the microscopic details of the system. However, when developing a QFT description for a given system, it can be challenging to derive the theory’s parameters from experiments, limiting the theory’s predictive power. Now, Torsten Zache of Heidelberg University, Germany, and colleagues have demonstrated a new approach to incorporate experimental data into the construction of a QFT . They show that the key building blocks for QFT can be derived from measurable correlation functions. They then provide an experimental validation of the approach using a quantum simulator. The result could allow researchers to use experiments to refine or develop QFTs for a broad range of experimental systems.To read more, click here.