2016/06/30 by Jérôme Dubail, Jean-Marie Stéphan, Jacopo Viti +1 · 4 citations
Mathematics · Physics and Astronomy · #Action (physics) #Cold Atom Physics and Bose-Einstein Condensates #Conformal field theory #Conformal map #Effective action #Effective field theory #Electron #Fermi Gamma-ray Space Telescope #Fermi gas #Field (mathematics) #Geometry #Mathematics #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum entanglement #Quantum field theory #Quantum many-body systems #Quantum mechanics #Statistical physics #Theoretical physics #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.21468/scipostphys.2.1.002
published as SciPost Phys. 2, 002 (2017) · v2: expanded version, 22 pages, 4 figures
arxiv created 2016/11/14 · openalex publication_date 2017/02/13 · arxiv updated 2017/02/15 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Conformal field theory (CFT) has been extremely successful in describing large-scale universal effects in one-dimensional (1D) systems at quantum critical points. Unfortunately, its applicability in condensed matter physics has been limited to situations in which the bulk is uniform because CFT describes low-energy excitations around some energy scale, taken to be constant throughout the system. However, in many experimental contexts, such as quantum gases in trapping potentials and in several out-of-equilibrium situations, systems are strongly inhomogeneous. We show here that the powerful CFT methods can be extended to deal with such 1D situations, providing a few concrete examples for non-interacting Fermi gases. The system's inhomogeneity enters the field theory action through parameters that vary with position; in particular, the metric itself varies, resulting in a CFT in curved space. This approach allows us to derive exact formulas for entanglement entropies which were not known by other means.