Ultra spin liquid in Lu3Cu2Sb3O14 V. R. Shaginyan, A. Z. Msezane, S. A. Artamonov, G. S. Japaridze and Y. S. Leevik EPL, 136 1 (2021) 17003 Published online: 28 December 2021 DOI: 10.1209/0295-5075/ac2651