Physics news · March 2026

Real memory cells reveal a thermodynamic limit stricter than Landauer’s

Physics 20 March 2026 · Physical Review Letters

Takase Shimizu, Kensaku Chida, Gento Yamahata and Katsuhiko Nishiguchi measured the energetics of information erasure directly in silicon dynamic random-access-memory cells, counting capacitor charges at the single-electron level.

They found that erasure efficiency falls as the target error probability drops, and that the Landauer limit of kT ln 2 per bit is never reached — even for effectively infinite-time erasure. The reason is a thermodynamic constraint specific to real memory: the initial state cannot be prepared in true thermal equilibrium, forbidding the quasistatic operation that the Landauer bound assumes.

The work shows that practical devices obey tighter limits than the textbook ideal, and charts an experimental route to discovering such constraints in the thermodynamics of computation.

Source

Physical Review Letters · further coverage.