Field-induced Bose-Einstein condensation in zigzag spin chain KGaCu(PO4)2

R Chen; H J Hu; Z Qu; T Li; C B Liu; C L Wang; S J Sun; C Dong; Y Qiu

doi:10.1088/1361-648X/ad15c9

Field-induced Bose-Einstein condensation in zigzag spin chain KGaCu(PO₄)₂

J Phys Condens Matter. 2024 Jan 22;36(16). doi: 10.1088/1361-648X/ad15c9.

Authors

R Chen¹, H J Hu¹, Z Qu¹, T Li², C B Liu^{2

3}, C L Wang¹, S J Sun¹, C Dong², Y Qiu¹

Affiliations

¹ Department of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000, People's Republic of China.
² Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
³ College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China.

PMID: 38096589
DOI: 10.1088/1361-648X/ad15c9

Abstract

Single crystals of GaKCu(PO₄)₂were synthesized using the hydrothermal method, and subsequent measurements of specific heat, magnetic susceptibility, and high-field magnetization were performed. A broad peak is observed in the magnetic susceptibility and specific heat curves, with the maximum values appearing at about 11.5 K and 5.29 K, respectively. The highest maximum peak value of susceptibility is observed when the magnetic field is applied along thec-axis, followed by thea-axis,b-axis, and polycrystalline samples. These indicate that the system exhibits one-dimensional magnetism and the magnetic easy axis is thecaxis. The magnetization at 2 K reveals the occurrence of a field-induced Bose-Einstein condensation (BEC) phase within the magnetic field range of approximately 8-12 T. High-field magnetization up to 40 T indicates that the compound reaches magnetization saturation as the field exceedsH_s= 12 T. Through systematic measurements, a field-temperature (H-T) phase diagram was constructed, and dome-like phase boundaries were observed. The findings suggest that GaKCu(PO₄)₂is a spin gap system and a promising candidate for studying BEC of magnons due to its phase transition boundary occurring at low magnetic fields.

Keywords: Bose–Einstein condensation; GaKCu(PO4)2; high-field magnetization; one-dimensional spin system.