Topological metamagnetism : thermodynamics and dynamics of the transition in spin ice under uniaxial compression

This work was carried out within the framework of a Max-Planck independent research group on strongly correlated systems. We acknowledge financial support from the Deutsche Forschungsgemeinschaft through SFB 1143 (Project No. 247310070) and Cluster of Excellence ct.qmat (EXC 2147, Project No. 390858490), EPSRC (EP/T028637/1), ShanghaiTech University, Agencia Nacional de Promoción Científica y Tecnológica through PICT 2017-2347, and Consejo Nacional de Investigaciones Científicas y Técnicas through PIP 0446.Metamagnetic transitions are analogs of a pressure-driven gas-liquid transition in water. In insulators, they are marked by a superlinear increase in the magnetization that occurs at a field strength set by the spin exchange interactions. Here we study topological metamagnets, in which the magnetization is itself a topological quantity and for which we find a single transition line for two materials with substantially different magnetic interactions: the spin ices Dy2Ti2O7 and Ho2Ti2O7. We study single crystals under magnetic field and stress applied along the [001] direction and show that this transition, of the Kasteleyn type, has a magnetization versus field curve with upward convexity and a distinctive asymmetric peak in the susceptibility. We also show that the dynamical response of Ho2Ti2O7 is sensitive to changes in the Ho3+ environment induced by compression along [001]. Uniaxial compression may open up experimental access to equilibrium properties of spin ice at lower temperatures.Publisher PDFPeer reviewe

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Topological metamagnetism:thermodynamics and dynamics of the transition in spin ice under uniaxial compression

Metamagnetic transitions are analogs of a pressure-driven gas-liquid transition in water. In insulators, they are marked by a superlinear increase in the magnetization that occurs at a field strength set by the spin exchange interactions. Here we study topological metamagnets, in which the magnetization is itself a topological quantity and for which we find a single transition line for two materials with substantially different magnetic interactions: the spin ices Dy2Ti2O7 and Ho2Ti2O7. We study single crystals under magnetic field and stress applied along the [001] direction and show that this transition, of the Kasteleyn type, has a magnetization versus field curve with upward convexity and a distinctive asymmetric peak in the susceptibility. We also show that the dynamical response of Ho2Ti2O7 is sensitive to changes in the Ho3+ environment induced by compression along [001]. Uniaxial compression may open up experimental access to equilibrium properties of spin ice at lower temperatures