2016/07/31 by Christopher J. Turner, Konstantinos Meichanetzidis, Zlatko Papic +2 · 3 citations
Physics and Astronomy · #Boson #Effective field theory #Fermion #Mott insulator #Perturbation theory (quantum mechanics) #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum entanglement #Quantum many-body systems #Quantum mechanics #Statistical physics #Theoretical physics #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1038/ncomms14926
published as Nature Communications 8, 14926 (2017) · 7+2 pages, 4+1 figures
openalex publication_date 2017/04/05 · arxiv created 2017/04/27 · arxiv updated 2017/04/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Interacting bosons or fermions give rise to some of the most fascinating phases of matter, including high-temperature superconductivity, the fractional quantum Hall effect, quantum spin liquids and Mott insulators. Although these systems are promising for technological applications, they also present conceptual challenges, as they require approaches beyond mean-field and perturbation theory. Here we develop a general framework for identifying the free theory that is closest to a given interacting model in terms of their ground-state correlations. Moreover, we quantify the distance between them using the entanglement spectrum. When this interaction distance is small, the optimal free theory provides an effective description of the low-energy physics of the interacting model. Our construction of the optimal free model is non-perturbative in nature; thus, it offers a theoretical framework for investigating strongly correlated systems.