Recent Research

Possible Bose-Einstein condensation of magnons in an S=5/2 honeycomb lattice

Dr. Raman Sankar and his group, in collaboration with Prof. Kwang-Yong Choi at Sungkyunkwan University (Republic of Korea) investigated the Quantum magnets offer a unique platform for exploring exotic quantum phases and quantum phase transitions through external magnetic fields. A prominent example is the field-induced Bose–Einstein condensation (BEC) of magnons near the saturation field. While this behavior has been observed in low-spin systems, its realization in high-spin, quasi-two-dimensional magnets—where multiple on-site excitations are possible—remains exceptionally rare. Here, we report thermodynamic and density functional theory results on single crystals of the honeycomb-lattice antiferromagnet K4MnMo4O15 with S = 5/2 . The system undergoes a field-induced transition to a fully polarized state at the critical field μ0Hs = 6.4 T. Our results reveal possible thermodynamic signatures of magnon BEC, TN ∼ (Hs −H)2/d (d = 3), expanding the purview of BEC-driven quantum criticality to a high-spin, quasi-two-dimensional antiferromagnets with negligibly small anisotropy.

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Journal Links: https://journals.aps.org/prb/pdf/10.1103