Heat engine driven by purely quantum information.
The key question of this Letter is whether work can be extracted from a heat engine by using purely quantum mechanical information. If the answer is yes, what is its mathematical formula? First, by using a bipartite memory we show that the work extractable from a heat engine is bounded not only by the free energy change and the sum of the entropy change of an individual memory but also by the change of quantum mutual information contained inside the memory. We then find that the engine can be driven by purely quantum information, expressed as the so-called quantum discord, forming a part of the quantum mutual information. To confirm it, as a physical example we present the Szilard engine containing a diatomic molecule with a semipermeable wall.
Department of Physics, Pusan National University, Busan 609-735, Korea.
Jung Jun
JJ
Park
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Kang-Hwan
KH
Kim
The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8302, Japan and Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan.
Takahiro
T
Sagawa
Department of Physics Education, Pusan National University, Busan 609-735, Korea.
Sang Wook
SW
Kim