SKM 2023 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 40: Stochastic Thermodynamics

DY 40.1: Vortrag

Donnerstag, 30. März 2023, 10:00–10:15, ZEU 250

Optimized Work Protocols for the Higgs RNA-Model — •Peter Werner and Alexander K. Hartmann — Institute of Physics, University of Oldenburg, Germany

When a system is driven from one state to another in a finite amount of time t∈[0,…,τ] by changing an external control parameter according to a protocol λ(t), some work W is performed. Here ⟨ W ⟩ ≥ Δ F holds, where Δ F is the equilibrium free energy difference between initial and final states. The protocol λ^*(t) minimizing the average amount of work is of interest, since it tightens the upper bound to Δ F. The optimum protocols of simple Brownian-particle systems exhibit distinct jumps especially at the beginning and end of the process [1,2] and it was speculated that these are a generic feature for arbitrary systems.

Here the many-particle Higgs RNA model [3] is considered, where work is performed by stretching the RNA through changing an external force. For this model, an exact calculation of the free-energy differences Δ F and the sampling of the equilibrium initial state can be performed in polynomial time. The work processes are realized by means of non-equilibrium Monte-Carlo simulations [4]. The optimum protocols are obtained numerically with the parallel-tempering approach. Also for this complex system, the optimum protocols exhibit distinct jumps at the beginning and end.

[1] T. Schmiedl and U. Seifert, Phys. Rev. Lett., 98, 108301 (2007)

[2] H. Then and A. Engel, Phys. Rev. E 77, 041105 (2008)

[3] P. G. Higgs, Phys. Rev. Lett., 76, 704 (1996)

[4] P. Werner and A. K. Hartmann, Phys. Rev. E 104, 034407 (2021)