1212.0407 (Hiroyasu Tajima)

A New Version of the Second Law of Information Thermodynamics Using
Entanglement Measure    [PDF]

Hiroyasu Tajima

We present a new version of the second law of information thermodynamics using an entanglement measure as the information content. In the new version $W_{\mathrm{ext}}\le-\Delta F+k_{B}TI_{\mathrm{E}}$, the new information $I_{\mathrm{E}}$ is the amount of the entanglement taken from the system through a unitary interaction between the system and the probe. The upper bound of the new second law is always achievable in the approximation such that the upper bound of the standard second law $W_{\mathrm{ext}}\le -\Delta F$ is always achievable. We also prove that when the system is a two-level system and when we perform only thermodynamic operations such that the equality of $W_{\mathrm{ext}}\le -\Delta F$ is achieved, we can always achieve the new upper bound without the above approximation, whereas under the same assumption as above there exists a measurement for which the upper bound of $W_{\mathrm{ext}}\le-\Delta F+k_{B}TI_{\mathrm{QC}}$ [Phys. Rev. Lett. 100, 080403 (2008)] cannot be achieved irrespective of the feedback.

View original: http://arxiv.org/abs/1212.0407