@article{PhysRevLett.112.030602,
  title = {Nanoscale Heat Engine Beyond the Carnot Limit},
  author = {Ro\ss{}nagel, J. and Abah, O. and Schmidt-Kaler, F. and Singer, K. and Lutz, E.},
  journal = {Phys. Rev. Lett.},
  volume = {112},
  issue = {3},
  pages = {030602},
  numpages = {5},
  year = {2014},
  month = {Jan},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevLett.112.030602},
  url = {https://link.aps.org/doi/10.1103/PhysRevLett.112.030602}
}