Maxwell's demon, the second law, and the minimum energy cost for measurement and erasure of information

The second law of thermodynamics presupposes a clear-cut distinction between the controllable and uncontrollable degrees of freedom by means of macroscopic operations. The cutting-edge technologies in quantum information and nano-science seem to force us to abandon such a notion in favor of the distinction between the accessible and inaccessible degrees of freedom. In this talk, I will discuss the implications of this paradigm shift by focusing on how the second law of thermodynamics can be generalized in the presence of a feedback control [1]. I will also discuss the minimum work required for measurement and erasure of information [2]. The Jarzynski equality has to be generalized in the presence of feedback control [3], as confirmed experimentally using polystyrene beads [4]. References[1] T. Sagawa and M. Ueda, Phys. Rev. Lett. 100, 080403 (2008).[2] T. Sagawa and M. Ueda, Phys. Rev. Lett. 102, 250602 (2009).[3] T. Sagawa and M. Ueda, Phys. Rev. Lett. 104, 090602 (2010).[4] S. Toyabe, T. Sagawa, M. Ueda, E. Muneyuki, and M. Sano, to appear in Nature Physics, arXiv:1009.5287 (2010).