Measurement of second-order response without perturbation

Abstract

We study the second order response functions of a colloidal particle being subjected to an anharmonic potential. Contrary to typical response measurements which require an external perturbation, here we experimentally confirm a recently developed approach where the system's susceptibilities up to second order are obtained from the particle's equilibrium trajectory [PCCP $17$, 6653 (2015)]. The measured susceptibilities are in quantitative agreement with those obtained from the response to an external perturbation.

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References in corpus (6)

• Fluctuations and response of nonequilibrium states
• The Einstein relation generalized to non-equilibrium
• Fluctuation relations in simple examples of non-equilibrium steady states
• Frenetic aspects of second order response
• Fluctuation dissipation relations in stationary states of interacting Brownian particles under shear
• Nonlinear susceptibilities and the measurement of a cooperative length

Cited by in corpus (4)

• Temperature in and out of equilibrium: a review of concepts, tools and attempts
• Response theory: a trajectory-based approach
• The Many Faces of Fluctuation-Dissipation Relations Out of Equilibrium
• A Thermodynamic Non-Linear Response Relation