Field-controlled magnetic order in the quantum spin-ladder system (Hpip)2CuBr4
Neutron diffraction is used to investigate the field-induced, antiferromagnetically ordered state in the two-leg spin-ladder material (Hpip)(2)CuBr4. This "classical" phase, a consequence of weak interladder coupling, is nevertheless highly unconventional: its properties are influenced strongly by the spin Luttinger-liquid state of the ladder subunits. We determine directly the order parameter (transverse magnetization), the ordering temperature, the spin structure, and the critical exponents around the transition. We introduce a minimal microscopic model for the interladder coupling and calculate the quantum fluctuation corrections to the mean-field interaction.
Keywords: antiferromagnetic materials ; copper compounds ; critical exponents ; fluctuations ; Luttinger liquid ; magnetic moments ; magnetic structure ; magnetisation ; magnetocaloric effects ; Monte Carlo methods ; Neel temperature ; neutron diffraction ; organic compounds ; X-Y model ; Criticality ; Dynamics ; Chains
Record created on 2009-03-12, modified on 2016-08-08