RT Journal Article
T1 Phase diagram of the bosonic double-exchange model
A1 Alonso, J. L.
A1 Cruz, A.
A1 Fernández Pérez, Luis Antonio
A1 JIménez, S.
A1 Martín Mayor, Víctor
A1 Ruiz-Lorenzo, J. J.
A1 Tarancón, A.
AB 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.
PB American Physical Society
SN 1098-0121
YR 2005
FD 2005-01-14
LK https://hdl.handle.net/20.500.14352/51927
UL https://hdl.handle.net/20.500.14352/51927
LA eng
NO © 2005 The American Physical Society. It is a pleasure to thank F. Guinea for useful conversation at the beginning of this work. We have maintained interesting discussions with A. Pelissetto regarding the large-N approximation. This work has been partially supported through research contracts FPA2001-1813, FPA2000-0956, BFM2001-0718, BFM2003-8532, PB98-0842 sMCyTd and HPRN-CT-2002-00307 sEUd. We have used the PentiumIV cluster RTN3 at the Universidad de Zaragoza for the simulations. S.J. was supported by DGA.
NO DGA
DS Docta Complutense
RD 18 dic 2025