New high magnetic field phase of the frustrated S = 1/2 chain compound LiCuVO4

Abstract

Magnetization of the frustrated S = 1/2 chain compound LiCuVO4, focusing on high magnetic field phases, is reported. Besides a spin-flop transition and the transition from a planar spiral to a spin modulated structure observed recently, an additional transition was observed just below the saturation field. This newly observed magnetic phase is considered as a spin nematic phase, which was predicted theoretically but was not observed experimentally. The critical fields of this phase and its dM/dH curve are in good agreement with calculations performed in a microscopic model (M. E. Zhitomirsky and H. Tsunetsugu, preprint, arXiv:1003.4096v2).PACS numbers: 75.50. Ee, 75.10.Jm, 75.10.Pq Unconventional magnetic orders and phases in frustrated quantum spin chains are attractive issues, because they appear under a fine balance of the exchange interactions and are sometimes caused by much weaker interactions or fluctuations. 1-4

Dynamics of linarite: Observations of magnetic excitations

“…One of them expected just below saturation is the quadrupolar state of bound magnon pairs which is termed the spin-nematic state 19 . The J 1 -J 2 model has been used to describe various quasi-1D edge-sharing cuprates 12,[21][22][23][24][25][26][27][28][29] . Unfortunately, for many of the candidates for exhibiting multipolar phases, the involved AFM magnetic couplings and thus the saturation field are quite large, making it difficult to probe the multipolar phases.…”

NaCuMoO4(OH) as a Candidate Frustrated J1–J2 Chain Quantum Magnet

“…In a single crystal of LiCuVO 4 , a linear variation in magnetization has been observed just below the saturation at 1.3 K, which may be associated with a spin nematic order [30]. Such a linear variation is not discernible in Fig.…”

“…It has been shown using large single crystals that LiCuVO 4 exhibits an incommensurate helical order at low fields [25][26][27][28][29], which may be a 3D analogue of the vector chirality order in the J 1 -J 2 chain, and a longitudinal SDW order at intermediate fields [26][27][28][29]. Furthermore, a spin nematic phase, a 3D analogue of the spin nematic state, has been suggested slightly below the saturation field of 44.4 T at H c, where the magnetization shows a linear field dependence [30]. However, the presence of the spin nematic phase is still unclear because of the high saturation field.…”

“…One more important requirement for a good candidate compound is the availability of a large and clean single crystal. Among the compounds shown in Table I [20][21][22], and LiCuVO 4 [23][24][25][26][27][28][29][30][31]. However, "a cleanness" of these crystals seems unsatisfactory: a natural crystal of PbCuSO 4 (OH) 2 is contaminated by impurities, and the two Li-containing crystals seem to suffer from Li deficiency or an interchange between Li and Cu atoms [24].…”

Dielectric anomaly in the quasi-one-dimensional frustrated spin-12system Rb2(Cu1−Yasui1, Yanagisawa2, Okazaki3 et al. 2013Phys. Rev. B150120View full textAdd to dashboardCite

“…Note that exotic quantum phases such as spin-nematic, quadrupolar-order, and chiral-order phases are theoretically predicted in the CuO 2 ribbon chain systems [15][16][17] and a possible existence of the spin-nematic phase was experimentally reported in LiVCuO 4 . 18 We have studied the CuO 2 ribbon chain systems to clarify the multiferroic nature and search for exotic effects inherent to their quantum nature. The authors' group found that LiVCuO 4 2,4,6 and PbCuSO 4 (OH) 2 7,14 exhibit a direct transition from a paramagnetic and paraelectric phase to a multiferroic phase at transition temperature T N =2.4 K and 2.8 K, respectively.…”