Quantum phase transition in Pr_{2}CuO_{4} to collinear non spinflop state in magnetic field: A neutron diffraction study
Abstract
In the external field applied to the tetragonal antiferromagnet Pr_{2}CuO_{4}, a transition is discovered from the phase with orthogonal antiferromagnetic spin subsystems along [1,0,0] and [0,1,0] to the phase with collinear spins, which are inclined about 45° to the field. This phase is shown to be due to the interplane pseudodipolar interaction, and transforms into the spinflop phase (S⊥H) asymptotically at very high field. The discovered phase transition is of first order, if the field is along [1,0,0], or [0,1,0], and becomes of second order if the field is slightly inclined to these axes. It holds at T = 0 and is a quantum one, with the transition field being the critical point and the angle between two subsystems below the critical point being the order parameter.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 February 2003
 DOI:
 10.1209/epl/i2003001621
 arXiv:
 arXiv:condmat/0207197
 Bibcode:
 2003EL.....61..534P
 Keywords:

 75.25.+z;
 75.30.Kz;
 75.50.Ee;
 Spin arrangements in magnetically ordered materials;
 Magnetic phase boundaries;
 Antiferromagnetics;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 doi:10.1209/epl/i2003001621