# Publications

Below is a list of scientific articles that I have (co-) authored.

## Preprints

*Information Arbitrage in Bipartite Heat Engines*

Matthew P. Leighton, Jannik Ehrich, and David A. Sivak (arXiv)

_{ Bipartite heat engines working between heat reservoirs at different temperatures must behave as information engines to produce net output work. Study of several model system illustrating the relationship between heat and information engines.}

## Published Articles

*Unlocking the potential of information flow: Maximizing free-energy transduction in a model of an autonomous rotary molecular motor*

Mathis Grelier, David A. Sivak, and Jannik Ehrich

Physical Reviev E**109**, 034115 (2024) (arXiv)

_{ Optimization of a discrete-state model of the molecular motor FoF1 ATP-synthase for output power, finding that information transduction is not needed for optimal performance in isothermal conditions. When the two machine components are in contact with heat baths at different temperatures, information flow becomes a valuable ressource.}*Information engine in a nonequilibrium bath*

Tushar K. Saha, Jannik Ehrich, Momčilo Gavrilov, Susanne Still, David A. Sivak, and John Bechhoefer

Physical Reviev Letters**131**, 057101 (2023) (arXiv

_{ Experimental study of an information ratchet subjected to additional nonequilibrium fluctuations, boosting output power by up to an order of magnitude, and theoretical analysis of engine efficiency showing that information engines in nonequilibrium baths can greatly outperform conventional engines}*Energetic cost of feedback control*

Jannik Ehrich, Susanne Still, and David A. Sivak

Physical Reviev Research**5**, 023080 (2023) (arXiv)

_{ Analysis of a thermodynamic process with repeated feedback, emphasizing that the controller is a physical system interacting with the feedback-controlled subsystem through interaction potentials, and derivation of minimal work needed to achieve feedback control}*Energy and information flows in autonomous systems*

Jannik Ehrich and David A. Sivak

Frontiers in Physics**11**, 1108357 (2023) (arXiv)

_{ Review of recent progress in the study of information flow in bipartite stochastic systems, such as biomolecular sensors and strongly-coupled two-component molecular machines, and gentle introduction into the information-flow formalism}*Bayesian information engine that optimally exploits noisy measurements*

Tushar K. Saha, Joseph N. E. Lucero, Jannik Ehrich, David A. Sivak, and John Bechhoefer

Physical Review Letters**129**, 130601 (2022) (arXiv)

**(Editors’ Suggestion, Synopsis in Physics)**

_{ Experimental realization of an information ratchet with measurement errors, phase transition in performance at a critical signal-to-noise ratio below which no work extraction is possible, and Bayesian estimates of system positions drastically increases performance}*Maximal fluctuation exploitation in Gaussian information engines*

Joseph N. E. Lucero, Jannik Ehrich, John Bechhoefer, and David A. Sivak

Physical Review E**103**, 022140 (2021) (arXiv)

_{ Analysis of masked Markovian jump process, comparison of different lower bounds on entropy production from partial observation, and calculation of tightest bound by fitting a generating model to the observable data}*Tightest bound on hidden entropy production from partially observed dynamics*

Jannik Ehrich

Journal of Statistical Mechanics: Theory and Experiment, 083214 (2021) (arXiv)

_{ Exploration of performance limits of a model of a realistic information engine that can store output energy, finding that restricting engine output to work against external force can limit information-to-energy performance, and investigation of tradeoff between input work and output work}*Maximizing power and velocity of an information engine*

Tushar K. Saha, Joseph N. E. Lucero, Jannik Ehrich, David A. Sivak, and John Bechhoefer

Proc. Natl. Acad Sci. USA**118**, e2023356118 (2021) (arXiv)

**(News coverage on SFU News, see PNAS Commentary)**

_{ Experimental realization of an “information ratchet” which rectifies thermal fluctuations of a micron-sized bead to lift it against gravity, optimization via theory of mean first-passage times, power and velocity an order of magnitude higher than in previously reported engines}*Free energy transduction within autonomous systems*

Steven J. Large, Jannik Ehrich, and David A. Sivak

Physical Review E**103**, 022140 (2021) (arXiv)

_{ Introduction of TAFER (transduced additional free energy rate) to quantify how one part of a strongly coupled system drives another (“downstream”) part, illustration with a model system, and connection to excess power and entropy production }*Optimal finite-time bit erasure under full control*

Karel Proesmans, Jannik Ehrich, and John Bechhoefer

Physical Review E**102**, 032105 (2020) (arXiv)

_{ Generalization of finite-time Landauer principle to partial erasure, detailed study of example systems, and full details of derivation of bounds on minimum dissipation }*Finite-time Landauer Principle*

Karel Proesmans, Jannik Ehrich, and John Bechhoefer

Physical Review Letters**125**, 100602 (2020) (arXiv)

**(Editors’ Suggestion, featured on phys.org)**

_{ Refined Landauer limit for bit erasure in finite time, simple bounds on erasure cost, and a method for finding minimum-dissipation erasure protocols}*Micro-reversibility and thermalization with collisional baths*

Jannik Ehrich, Massimiliano Esposito, Felipe Barra, and Juan M.R. Parrondo

Physica A**552**, 122108 (2020) (arXiv)

_{ Semi-classical analysis of a system in a collisional bath, showing how micro-reversibility needs all canonical variables and conservation of phase-space volume, and that, otherwise, violations of the second law emerge}*Approximating microswimmer dynamics by active Brownian motion: Energetics and efficiency*

Jannik Ehrich and Marcel Kahlen

Physical Review E**99**, 012118 (2019) (arXiv)

_{ Dynamics of a microswimmer are shown to approximate active Brownian motion, comparison of energy dissipation rates of approximation and full model, introduction of a swimming efficiency }*Hidden slow degrees of freedom and fluctuation theorems: an analytically solvable model*

Marcel Kahlen and Jannik Ehrich

Journal of Statistical Mechanics: Theory and Experiment, 063204 (2018) (arXiv)

_{ Analytically tractable model illustrating how unobserved degrees of freedom modify fluctuation theorems for the apparent entropy production and calculation of full, non-Markovian marginal entropy production via path integrals }*Stochastic thermodynamics of interacting degrees of freedom: Fluctuation theorems for detached path probabilities*

Jannik Ehrich and Andreas Engel

Physical Review E**96**, 042129 (2017) (arXiv)

_{ General analysis of systems with interacting degrees of freedom, derivation of general fluctuation theorems capable of disentangling their interaction, and recovery of many known fluctuation theorems for special cases }

## Thesis

*Coupled and Hidden Degrees of Freedom in Stochastic Thermodynamics*

Carl von Ossietzky Universität Oldenburg, 2020 (arXiv)