Honeycomb Heisenberg spin ladder: Unusual ground state and thermodynamic properties Yang Zhao, Wei Li, Bin Xi, Shi-Ju Ran, Yuan-Yuan Zhu, Bing-Wu Wang, Song Gao and Gang Su EPL, 104 5 (2013) 57009 Published online: 24 December 2013 DOI: 10.1209/0295-5075/104/57009