Theory Seminar

KEK 素粒子原子核研究所・理論セミナー

TITLE:
Information Thermodynamics
(Japanese/English: depends on audience)
SPEAKER:
沙川貴大(Takahiro Sagawa)
(東京大学大学院理学系研究科物理学専攻)
DATE:
December 14(Mon.) 15:00-
PLACE:
Kenkyu Honkan 3F RM 322

(ABSTRACT)
The fundamental energy cost needed for information processing has been a topic of active researches ever since the proposal of "Maxwell's demon," which has the capability to perform information processing at a microscopic level. In this seminar, I'd like to talk about the fundamental lower bounds of the thermodynamic energy cost needed for information processing such as feedback control, measurement, and information erasure. The lower bound on the erasure validates Landauer's principle for a symmetric memory; for other cases, the bound indicates the breakdown of the principle. Based on the general results, we propose a new resolution of the long-standing paradox of the Maxwell's demon. Our results constitute the second law of "information thermodynamics," in which the information content and thermodynamic variables are treated on an equal footing.

[1] T. Sagawa and M. Ueda, Phys. Rev. Lett. 100, 080403 (2008).
[2] T. Sagawa and M. Ueda, Phys. Rev. Lett. 102, 250602 (2009).