Gate abstractions and reversibility: On the logical-physical link

Logic gates rendered in digital circuit diagrams refer both to abstract logical transformations of Boolean variables and to the physical structures and processes that realize these transformations. The logical and physical aspects are related in a manner that has implications for energy efficient computing; Landauer's Principle (LP) imposes efficiency limits on gates that irreversibly discard information but imposes no such limits on gates that do not. In this paper, we explore the logical-physical link and its dissipative consequences from a fundamental perspective. We provide a systematic characterization of this link, and use the resulting framework to clarify necessary conditions for physically reversible operation of logically reversible and logically irreversible gates in circuit environments.