Work and Efficiency of Quantum Otto Cycles in Power Law Trapping   Potentials
  We study the performance of a quantum Otto cycle driven by trapping potentials of the form $V_t(x) \sim x^{2q}$. This family of potentials possesses a simple scaling property which allows for analytical insights into the efficiency and work output of the cycle. We show that, while both the mean work output and the efficiency of two Otto cycles in different trapping potentials can be made equal, the work probability distribution will still be strongly affected by the difference in structure of the energy levels. Lastly, we perform a comparison of quantum Otto cycles in various physically relevant scenarios and find that in certain instances, the efficiency of the cycle is greater when using potentials with larger values of $q$, while, in other cases, with harmonic traps. 
Yuanjian Zheng, Dario Poletti
cond-mat.stat-mech quant-ph