2014/10/29 by Gergely Endrődi, Endrodi, G. · 3 citations
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #High-Energy Particle Collisions Research #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Nuclear Theory (nucl-th) #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1410.8028
openalex publication_date 2014/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
I revisit the problem of a charged particle on a two-dimensional lattice immersed in a constant (electro)magnetic field, and discuss the energy spectrum - Hofstadter's butterfly - from a new, quantum field theoretical perspective. In particular, I point out that there is an intricate interplay between a) the structure of the butterfly at low magnetic flux, b) the absence of asymptotic freedom in QED and c) the enhancement of the quark condensate by a magnetic field at zero temperature. I proceed to discuss the response of the QCD condensate to the magnetic field at nonzero temperatures in four space-time dimensions, present the resulting phase diagram and compare it to low-energy model predictions.