Resonating valence bond

Resonating valence bond
Name	Resonating valence bond
Field	Condensed matter physics
Introduced	1970s
Proponents	Philip W. Anderson, P. W. Anderson, Patrick A. Lee
Notable cases	High-temperature superconductivity

Resonating valence bond is a theoretical framework in condensed matter physics proposing that electronic pairing and quantum spin correlations arise from superpositions of singlet bond configurations. It was introduced to explain phenomena in strongly correlated materials and has influenced research on superconductivity, quantum spin liquids, and low-dimensional magnetism. The approach connects ideas from quantum mechanics, many-body theory, and lattice models to predict emergent phases beyond conventional order parameters.

History and development

The concept was articulated in the 1970s by physicists associated with Bell Labs, Princeton University, and Bell Laboratories who sought alternatives to conventional descriptions used in Landau Fermi liquid theory, BCS theory, and the then-dominant paradigms of magnetic ordering. Early proponents published work influenced by discussions at institutions such as Institute for Advanced Study, Massachusetts Institute of Technology, and Harvard University, prompting responses from researchers at University of Cambridge, Stanford University, and University of California, Berkeley. Debates about its relevance surged following the discovery of high-temperature superconductivity in bedt-ttf salts, cuprates, and experimental results from groups at IBM Research, Los Alamos National Laboratory, and Bell Labs that explored Hubbard and t-J models. Subsequent developments involved collaborations with theorists from University of Tokyo, École Normale Supérieure, and Max Planck Institute for Physics of Complex Systems.

Theoretical foundations

RVB builds on a foundation of quantum superposition and entanglement studied at centers like CERN, Niels Bohr Institute, and Perimeter Institute. Foundational calculations used lattice Hamiltonians developed in the context of the Hubbard model and the t-J model, with mathematical techniques honed at Princeton Plasma Physics Laboratory and Los Alamos National Laboratory. Formalism draws on methods popularized in works from Isaac Newton Institute, Kavli Institute for Theoretical Physics, and Royal Society-affiliated researchers, connecting to concepts explored by scholars at University of Oxford, Caltech, and Columbia University. Influential computational approaches emerged from collaborations with groups at Argonne National Laboratory, Oak Ridge National Laboratory, and Hitachi Global Sciences.

RVB states and wavefunctions

RVB states are expressed as superpositions of singlet coverings on lattices studied at institutions such as University of Illinois Urbana-Champaign, University of Michigan, and University of Texas at Austin. Wavefunction ansätze were developed alongside variational Monte Carlo techniques refined at Los Alamos National Laboratory, IBM Research, and ETH Zurich. Specific constructions—short-range RVB, long-range RVB, projected BCS states—were analyzed in studies involving researchers from University of Chicago, University of Cambridge, and Yale University. Topological variants and chiral RVB wavefunctions attracted attention from theorists at Max Planck Institute for Quantum Optics, Tokyo Institute of Technology, and Seoul National University.

Applications in condensed matter physics

RVB ideas influenced interpretations of superconductivity in families represented by La2-xSrxCuO4, YBa2Cu3O7-x, and organics like κ-(BEDT-TTF)2Cu2(CN)3. The framework was adapted by groups at Brookhaven National Laboratory, SLAC National Accelerator Laboratory, and National High Magnetic Field Laboratory to study quantum spin liquids on lattices realized in materials investigated by teams at Swiss Federal Institute of Technology Lausanne and University of St Andrews. Links to topological order and anyon statistics were pursued by collaborations including researchers from Microsoft Research, Institute for Quantum Computing, and University of Maryland. RVB-inspired models informed numerical studies at Los Alamos National Laboratory, Lawrence Berkeley National Laboratory, and Rutherford Appleton Laboratory to explore metal-insulator transitions and unconventional pairing.

Experimental evidence and signatures

Experimental probes conducted at facilities like Argonne National Laboratory, Brookhaven National Laboratory, and ISIS Neutron and Muon Source sought RVB signatures via neutron scattering, muon spin rotation, and angle-resolved photoemission spectroscopy practiced at Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, and European Synchrotron Radiation Facility. Measurements reported by groups at University of Tokyo, University of Cambridge, and University of California, San Diego examined spin-gap behavior, fractionalized excitations, and absence of conventional symmetry breaking in candidate spin liquids such as triangular and kagome compounds studied by teams at University of Geneva, Rutgers University, and University of Tokyo. Resonant inelastic x-ray scattering experiments from Diamond Light Source and National Synchrotron Light Source provided complementary evidence for short-range singlet correlations.

Extensions and related theories

RVB has branched into frameworks connected with topological quantum field theory explored at Institute for Advanced Study, Perimeter Institute, and Max Planck Institute for Mathematics in the Sciences, and inspired approaches in quantum information science at MIT, Stanford University, and University of Waterloo. Connections to gauge theories and slave-particle formalisms were developed by groups at Harvard University, University of California, Santa Barbara, and Yale University. Modern extensions include tensor network adaptations pursued by researchers at University of Vienna, Flatiron Institute, and Institute of Physics, Chinese Academy of Sciences, and cold-atom emulations tested in laboratories at MIT, University of Cambridge, and ETH Zurich to simulate RVB-like Hamiltonians.

Category:Condensed matter physics