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 8 abr 2025