Thermodynamic evidence of a second skyrmion lattice phase and tilted conical phase in Cu\(_2\)0SeO\(_3\)

• Published in: arXiv.org
• Main Authors: Halder, M, Chacon, A, Bauer, A, Simeth, W, Mühlbauer, S, Berger, H, Heinen, L, Garst, M, Rosch, A, Pfleiderer, C
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 31.03.2021
• Subjects: Anisotropy; Critical field (superconductivity); Crystallography; Demagnetization; Hypothetical particles; Low temperature; Magnetic fields; Magnetism; Magnetization; Neutron scattering; Particle theory; Temperature dependence
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2103.16238

Precision measurements of the magnetization and ac susceptibility of Cu\(_2\)0SeO\(_3\) are reported for magnetic fields along different crystallographic directions, focussing on the border between the conical and the field-polarized state for a magnetic field along the \(\langle 100 \rangle\) axis, complemented by selected specific heat data. Clear signatures of the emergence of a second skyrmion phase and a tilted conical phase are observed, as recently identified by means of small-angle neutron scattering. The low-temperature skyrmion phase displays strongly hysteretic phase boundaries, but no dissipative effects. In contrast, the tilted conical phase is accompanied by strong dissipation and higher-harmonic contributions, while the transition fields are essentially nonhysteretic. The formation of the second skyrmion phase and tilted conical phase are found to be insensitive to a vanishing demagnetization factor. A quantitative estimate of the temperature dependence of the magnetocrystalline anisotropy may be consistently inferred from the magnetization and the upper critical field and agrees well with a stabilization of the low-temperature skyrmion phase and tilted conical state by conventional cubic magnetic anisotropies.