Spiral spin-liquid and the emergence of a vortex-like state in MnSc2S4

Gao, Shang; Zaharko, O.; Tsurkan, V.; Su, Yixi; White, J. S.; Tucker, Gregory S.; Roessli, B.; Bourdarot, F.; Sibille, Romain; Chernyshov, Dmitry; Fennell, T.; Loidl, A.; Rüegg, Christian

doi:10.1038/nphys3914

Cited by 120 publications

(149 citation statements)

References 43 publications

Supporting

Mentioning

140

Contrasting

Order By: Relevance

“…This anomaly is even more pronounced in the ultrasound attenuation as shown in previous experiments [15]. It was speculated that this anomalous behavior might be attributed to a frustration in the Mn diamond lattice induced by next-nearest-neighbour interactions, as recently discussed for another spinel compound, MnSc 2 S 4 [38,39]. The inclusion of farther spin interactions to our minimal model (1) might be appropriate.…”

Section: Discussionsupporting

confidence: 64%

Spin-lattice coupling in a ferrimagnetic spinel: Exotic H−T phase diagram of MnCr2S4 up to 110 T

et al. 2020

View full text Add to dashboard Cite

In antiferromagnets, the interplay of spin frustration and spin-lattice coupling has been extensively studied as the source of complex spin patterns and exotic magnetism. Here, we demonstrate that, although neglected in the past, the spin-lattice coupling is essential to ferrimagnetic spinels as well. We performed ultrahigh-field magnetization measurements up to 110 T on a Yafet-Kittel ferrimagnetic spinel, MnCr2S4, which was complemented by measurements of magnetostriction and sound velocities up to 60 T. Classical Monte Carlo calculations were performed to identify the complex high-field spin structures. Our minimal model incorporating spin-lattice coupling accounts for the experimental results and corroborates the complete phase diagram, including two new highfield phase transitions at 75 and 85 T. Magnetoelastic coupling induces striking effects: An extremely robust magnetization plateau is embedded between two unconventional spin-asymmetric phases. Ferrimagnetic spinels provide a new platform to study asymmetric and multiferroic phases stabilized by spin-lattice coupling.

show abstract

Section: Discussionsupporting

confidence: 64%

Spin-lattice coupling in a ferrimagnetic spinel: Exotic H−T phase diagram of MnCr2S4 up to 110 T

et al. 2020

View full text Add to dashboard Cite

show abstract

“…One of the candidates is a two-dimensional monolayer system showing a noncoplanar magnetic structure [42][43][44][45]. It is also interesting to clarify the origin of multiple-Q magnetic orderings in three-dimensional compounds by our spin model: a scandium thiospinel MnSc 2 S 4 showing a triple-Q vortex crystal under an external magnetic field [46], a rare-earth borocarbide GdNi 2 B 2 C showing a double-Q ordering in the wide range of field-temperature phase diagram [47], and a strontium iron perovskite oxide SrFeO 3 , exhibiting several phases depending on magnetic field and temperature [48]. Interestingly, the transport measurements for SrFeO 3 imply that the phases include multiple-Q states in spite of the negligibly small contribution of the spin-orbit coupling.…”

Section: Summary and Concluding Remarksmentioning

confidence: 99%

Effective bilinear-biquadratic model for noncoplanar ordering in itinerant magnets

2017

View full text Add to dashboard Cite

Noncollinear and noncoplanar magnetic textures including Skyrmions and vortices act as emergent electromagnetic fields and give rise to novel electronic and transport properties. We here report a unified understanding of noncoplanar magnetic orderings emergent from the spin-charge coupling in itinerant magnets. The mechanism has its roots in effective multiple spin interactions beyond the conventional Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism, which are ubiquitously generated in itinerant electron systems with local magnetic moments. By carefully examining the higher-order perturbations in terms of the spin-charge coupling, we construct a minimal effective spin model composed of the bilinear and biquadratic interactions with particular wave numbers dictated by the Fermi surface. Taking two-dimensional systems as examples, we find that our effective model captures the underlying physics of the instability toward noncoplanar multiple-Q states discovered recently: a single-Q helical state expected from the RKKY theory is replaced by a double-Q vortex crystal with chirality density waves even for an infinitely small spin-charge coupling on generic lattices [R. Ozawa et al., J. Phys. Soc. Jpn. 85, 103703 (2016)], and a triple-Q Skyrmion crystal with a high topological number of two appears while increasing the spin-charge coupling on a triangular lattice [R. Ozawa, S. Hayami, and Y. Motome, Phys. Rev. Lett. 118, 147205 (2017)]. We find that by introducing an external magnetic field, our effective model exhibits a plethora of multiple-Q states. Our effective model will serve as a guide for exploring further exotic magnetic orderings in itinerant magnets, not only in two dimensions but also in three dimensions.

show abstract

“…These ideas have been quite successful in explaining the multiple transitions and incommensurate ground state of the singular material MnSc 2 S 4 7,8 , and very recent work has confirmed key SSL predictions 23 . In oxides, however, the search for SSL physics has focussed most intently on the compound CoAl 2 O 4 .…”

mentioning

confidence: 96%

Revisiting the ground state of CoAl2O4 : Comparison to the conventional antiferromagnet MnAl2O

MacDougall¹,

Aczel²,

Su³

et al. 2016

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

The A-site spinel material, CoAl2O4, is a physical realization of the frustrated diamond-lattice antiferromagnet, a model in which unique incommensurate or 'spin-spiral liquid' ground states are predicted. Our previous single-crystal neutron scattering study instead classified it as a 'kineticallyinhibited' antiferromagnet, where the long ranged correlations of a collinear Néel ground state are blocked by the freezing of domain wall motion below a first-order phase transition at T* = 6.5 K. The current paper provides new data sets from a number of experiments, which support and expand this work in several important ways. We show that the phenomenology leading to the kinetically-inhibited order is unaffected by sample measured and instrument resolution, while new low temperature measurements reveal spin correlations are unchanging between T = 2 K and 250 mK, consistent with a frozen state. Polarized diffuse neutron measurements show several interesting magnetic features, which can be entirely explained by the existence of short-ranged Néel order. Finally, and crucially, this paper presents some of the first neutron scattering studies of single crystalline MnAl2O4, which acts as an unfrustrated analogue to CoAl2O4 and shows all the hallmarks of a classical antiferromagnet with a continuous phase transition to Néel order at TN = 39 K. Direct comparison between the two compounds indicates that CoAl2O4 is unique, not in the nature of high-temperature diffuse correlations, but rather in the nature of the frozen state below T * . The higher level of cation inversion in the MnAl2O4 sample indicates that this novel behavior is primarily an effect of greater next-nearest-neighbor exchange.PACS numbers: 75.30.Ds, 75.50.Lk, 78.70.Nx The A-site spinels, AB 2 X 4 with A magnetic, have seen a surge of interest in the past decade, due to a series of interesting experimental observations 1-15 and theoretical predictions of novel spin-liquid ground states [16][17][18][19][20] . Magnetic cations in these materials comprise a bi-partite diamond lattice, and novel behavior is argued to be the result of a competition between nearest (J 1 ) and nextnearest (J 2 ) neighbor superexchange interactions 2,21 . This is demonstrated explicitly by the calculations of Bergman et al. 16 , who have shown for spin-only materials that the collinear Néel structure favored by J 1 is progressively destabilized with increasing J 2 , until a Lifshitz point is encountered at J2 J1 = 1 8 . For greater J 2 , the ground state is predicted to be a novel 'spiral spin liquid' (SSL) state characterized by fluctuations between an infinitely degenerate set of incommensurate spin spirals, whose propagation wavevectors form a series of calculable manifolds in reciprocal space ('spiral surfaces'). Further calculations [16][17][18] predict that these mass degeneracies are lifted by low-lying thermal or quantum fluctuations, driving first-order phase transitions via the order-by-disorder mechanism 22 to either unique spin spiral or Néel ordered states, depending o...

show abstract

Spiral spin-liquid and the emergence of a vortex-like state in MnSc2S4

Cited by 120 publications

References 43 publications

Spin-lattice coupling in a ferrimagnetic spinel: Exotic H−T phase diagram of MnCr2S4 up to 110 T

Spin-lattice coupling in a ferrimagnetic spinel: Exotic H−T phase diagram of MnCr2S4 up to 110 T

Effective bilinear-biquadratic model for noncoplanar ordering in itinerant magnets

Revisiting the ground state of CoAl2O4 : Comparison to the conventional antiferromagnet MnAl2O

Contact Info

Product

Resources

About