Nonequilibrium information erasure below kTln2

Abstract

PACS 05.70.Ln -Nonequilibrium and irreversible thermodynamics PACS 42.50.Wk -Mechanical effects of light on material media, microstructures and particles Abstract -Landauer's principle states that information erasure requires heat dissipation. While Landauer's original result focused on equilibrium memories, we here investigate the reset of information stored in a nonequilibrium state of a symmetric two-state memory. We derive a nonequilibrium generalization of the erasure principle and demonstrate that the corresponding bounds on heat and work may be reduced to zero. We further introduce reset protocols that harness energy and entropy of the initial preparation and so allow to reach these nonequilibrium bounds. We finally provide numerical simulations with realistic parameters of an optically levitated nanosphere memory that support these findings. Our results indicate that local dissipation-free information reset is possible away from equilibrium.

Experimental nonequilibrium memory erasure beyond Landauer's bound

“…Their information is lost when power is switched off. Recent theoretical results suggest that far-from-equilibrium physics may have a significant impact on the thermodynamic bounds of the erasure process [21][22][23]. In particular, work consump-FIG.…”

“…tion and heat dissipation may be controlled and reduced below the kT ln 2 limit when information is stored in a nonequilibrium state [23].…”

“…with a generalized nonequilibrium Landauer bound [23]. To this end, we introduce dynamically programmed control of anharmonic potentials for optical levitation as a powerful and versatile tool to modulate nonlinear potentials on fast timescales in the underdamped regime.…”

“…Because of the initial out-of-equilibrium state of the double-well system, Landauer's principle needs to be extended [21]. Applying the laws of thermodynamics to this nonequilibrium configuration, a generalized Landauer bound holds for the mean dissipated heat Q and the mean consumed work W in the reset phase [23],…”

“…The value of thus controls the departure from equilibrium of the initial memory state. We design and optimize the reset protocol in order to properly harness the preparation energy and entropy, and therefore minimize consumed work and dissipated heat [23]. Figure 2c shows the protocol used for the fast dynamical control of the three parameters α(t), β(t) and F (t) for an optimal information reset followed by a reinitialization of the nonequilibrium state.…”