Nearly critical ground state of LaCuO2.5
Abstract
Using a combination of analytical techniques and quantum Monte Carlo simulations we investigate the coupled spin-ladder system LaCuO2.5. At a critical ratio of the interladder to intraladder coupling (J|IH/J)c~0.11 we find a quantum phase transition between a Néel ordered and a disordered state. At criticality the uniform susceptibility behaves as χ(T)=aT2 with a universal prefactor. At intermediate temperatures the system crosses over to a ``decoupled ladders regime'' with pseudogap-type behavior, similar to uncoupled ladders. This can explain the gaplike experimental data for the magnetic susceptibility of LaCuO2.5 despite the presence of long-range Néel order.
- Publication:
-
Physical Review B
- Pub Date:
- March 1997
- DOI:
- 10.1103/PhysRevB.55.R6117
- arXiv:
- arXiv:cond-mat/9606089
- Bibcode:
- 1997PhRvB..55.6117T
- Keywords:
-
- Condensed Matter
- E-Print:
- 4 pages, RevTex, 2 figures. Revised version contains QMC data for larger lattices and a fit to experimental data