6533b830fe1ef96bd1297b25
RESEARCH PRODUCT
Antiferromagnetic Heisenberg chains with bond alternation and quenched disorder
Heiko RiegerFerenc IglóiYu-cheng Linsubject
PhysicsCondensed matter physicsDimerGeneral Physics and AstronomyFOS: Physical sciencesFunction (mathematics)Disordered Systems and Neural Networks (cond-mat.dis-nn)Type (model theory)Renormalization groupCondensed Matter - Disordered Systems and Neural NetworksCondensed Matter::Disordered Systems and Neural Networkschemistry.chemical_compoundchemistryPhase (matter)ExponentAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsSinglet statedescription
We consider S=1/2 antiferromagnetic Heisenberg chains with alternating bonds and quenched disorder, which represents a theoretical model of the compound CuCl_{2x}Br_{2(1-x)}(\gamma-{pic})_2. Using a numerical implementation of the strong disorder renormalization group method we study the low-energy properties of the system as a function of the concentration, x, and the type of correlations in the disorder. For perfect correlation of disorder the system is in the random dimer (Griffiths) phase having a concentration dependent dynamical exponent. For weak or vanishing disorder correlations the system is in the random singlet phase, in which the dynamical exponent is formally infinity. We discuss consequences of our results for the experimentally measured low-temperature susceptibility of CuCl_{2x}Br_{2(1-x)}(\gamma-{pic})_2.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-02-16 |