2007/03/29 by Max A. Metlitski, Subir Sachdev
Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Condensed matter physics #Delocalized electron #Electron #Ground state #Magnetic properties of thin films #Paramagnetism #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum spin liquid #Spin (aerodynamics) #Spin polarization #Spinon #Spins #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.76.064423
published as Physical Review B 76, 064423 (2007) · 30 pages, 9 figures
arxiv created 2007/03/29 · openalex publication_date 2007/08/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We describe the spin distribution in the vicinity of a nonmagnetic impurity in a two-dimensional antiferromagnet undergoing a transition from a magnetically ordered N'eel state to a paramagnet with a spin gap. The quantum critical ground state in a finite system has total spin S=1∕2 (if the system without the impurity had an even number of S=1∕2 spins), and recent numerical studies in a double layer antiferromagnet [K. H. H"oglund et al., Phys. Rev. Lett. 98, 087203 (2007)] have shown that the spin has a universal spatial form delocalized across the entire sample. We present the field theory describing the uniform and staggered magnetizations in this spin texture for two classes of antiferromagnets: (i) the transition from a N'eel state to a paramagnet with local spin singlets, in models with an even number of S=1∕2 spins per unit cell, which are described by a O(3) Landau-Ginzburg-Wilson field theory; and (ii) the transition from a N'eel state to a valence bond solid, in antiferromagnets with a single S=1∕2 spin per unit cell, which are described by a ``deconfined'' field theory of spinons.