%0 Journal Article
%A Alonso, J. L.
%A Cruz, A.
%A Fernández Pérez, Luis Antonio
%A JIménez, S.
%A Martín Mayor, Víctor
%A Ruiz-Lorenzo, J. J.
%A Tarancón, A.
%T Phase diagram of the bosonic double-exchange model
%D 2005
%@ 1098-0121
%U https://hdl.handle.net/20.500.14352/51927
%X The phase diagram of the simplest approximation to double-exchange systems, the bosonic double-exchange model with antiferromagnetic (AFM) superexchange coupling, is fully worked out by means of Monte Carlo simulations, large-N expansions, and variational mean-field calculations. We find a rich phase diagram, with no first-order phase transitions. The most surprising finding is the existence of a segmentlike ordered phase at low temperature for intermediate AFM coupling which cannot be detected in neutron-scattering experiments. This is signaled by a maximum (a cusp) in the specific heat. Below the phase transition, only short-range ordering would be found in neutron scattering. Researchers looking for a quantum critical point in manganites should be wary of this possibility. Finite-size scaling estimates of critical exponents are presented, although large scaling corrections are present in the reachable lattice sizes.
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