= Landauer's principle
<Landauer's principle> relates logically irreversible information erasure to thermodynamic cost. Resetting an initially equiprobable, uncorrelated one-bit memory to one <standard state> while coupled to a bath at <temperature> $T$ requires average <heat> release of at least $k_BT\ln2$ to the bath in the ideal cyclic setting.
The restriction matters: erasing one unknown bit is different from reversibly transforming a known state, and real devices can dissipate more. The <entropy> reduction of the memory must be compensated elsewhere. The bound therefore concerns information loss under specified physical conditions, rather than a universal cost for every logic operation.<Irreversibility and Heat Generation in the Computing Process by Rolf Landauer>[1961, logical irreversibility and heat generation]{ref}
A later <experiment> represented a bit by the two wells of a potential trapping one colloidal particle. Driving the particle distribution into a chosen well allowed dissipated <heat> during erasure to be compared with the bound. Approaching the reversible <limit> requires slow controlled operations; <measurement> of the work and <heat> connects the information statement to a physical apparatus.https://www.nature.com/articles/nature10872[Bérut and others, 2012, abstract and single-particle erasure experiment]{ref}
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