Are quantum thermodynamic machines better than their classical counterparts? Arnab Ghosh, Victor Mukherjee, Wolfgang Niedenzu and Gershon Kurizki Eur. Phys. J. Special Topics, 227 15-16 (2019) 2043-2051 Published online: 05 March 2019 DOI: 10.1140/epjst/e2019-800060-7