Fluctuation-induced phase in in a transverse magnetic field: theory

Abstract

CsCuCl 3 is a quantum triangular antiferromagnet, ferromagnetically stacked, with an incommensurate (IC) structure due to a DzyaloshinskiiMoriya interaction. Because of the classical degeneracy caused by the frustration, fluctuations in CsCuCl 3 have extraordinarily large effects, such as the phase transition in longitudinal magnetic field (normal to the planes, parallel to the IC wavenumber q) and the plateau in q in transverse field (perpendicular to q). We argue that fluctuations are responsible also for the new IC phase discovered in transverse field near the Néel temperature T N , by T. Werner et al. [Solid State Commun. 102, 609 (1997)]. We develop and analyse the corresponding minimal Landau theory; the effects of fluctuations on the frustration are included phenomenologically, by means of a biquadratic term. The Landau theory gives two IC phases, one familiar from previous studies; properties of the new IC phase, which occupies a pocket of the temperature-field phase diagram near T N , agree qualitatively with those of the new phase found experimentally. 64.70.Rh, 75.10.Jm, 75.25.+z, 75.50.Ee

Spiral magnetic structure in spin-52frustrated trimerized chains in SrMn3P4OHase1, Pomjakushin2, Keller3 et al. 2011Phys. Rev. B

“…Competition between symmetric exchange and Dzyaloshinskii-Moriya (DM) interactions can produce spiral magnetic structures. Examples of materials are Ba 2 CuGe 2 O 7 , 40 CsCuCl 3 , 41 and CuB 2 O 4 . 42 A uniform component of DM vectors is necessary.…”

Effective Hamiltonians and dilution effects in Kagome and related anti-ferromagnets

“…This was independently posited phenomenologically [15]; it can be obtained analytically in a couple of ways using a perturbation expansion [12] around mean-field theory. 2 One obtains K ij = S 2 j 2 ij /8h loc , where the local field h loc is 2jS in a bisimplex lattice.…”

Electron Spin Resonance in Triangular Antiferromagnets

“…22,[60][61][62][63][64][65][66][67][68][69][70] The Cu 2+ ion is Jahn-Teller active, when it is surrounded octahedrally by anions. For this reason, CsCuCl 3 undergoes a structural phase transition at T t = 423 K. For T < T t , CuCl 6 octahedra are elongated along the one of the principal axes and the elongated axes form a helix along the c-axis with a repeat length of six.…”