Electronic Resource
[S.l.]
:
American Institute of Physics (AIP)
Journal of Applied Physics
67 (1990), S. 5221-5221
ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The antiferromagnetic two-impurity Kondo problem, involving two magnetic moments coupled antiferromagnetically to each other and also to a band of itinerant electrons, has been found to exhibit nontrivial behavior.1 We show analytically2 that the presence of a type of particle-hole symmetry guarantees a nonanalyticity in the ground-state energy as the antiferromagnetic RKKY coupling is varied relative to the Kondo temperature. This symmetry is not present in the generic antiferromagnetic two-impurity model. Previous work on the symmetric model1 has shown that the nonanalyticity is a second-order T=0 phase transition with diverging specific heat coefficient and staggered susceptibility. We have studied the effect of breaking the symmetry via an analytic large-N expansion and via Wilson's numerical renormalization group technique. The analytic work suggests that there may be no transition if the symmetry is broken. The preliminary numerical work suggests either that the transition survives, or that there is a well-defined crossover signalled by an order of magnitude or more enhancement of the specific heat coefficient. Further analytic and numerical work is in progress to resolve the dilemma.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.344616
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