The convergence of the steady-state fluctuation theorem (SSFT) is investigated in a shear-flow experiment performed in a dusty plasma. This medium has a viscoelastic property characterized by the Maxwell relaxation time ${\tau }_M$. Using measurements of the time series of the entropy production rate, for subsystems of various sizes, it is discovered that the SSFT convergence time decreases with the increasing system size until it eventually reaches a minimum value of ${\tau }_M$, no matter the size of the subsystem. This result indicates that the convergence of the SSFT is limited by the energy-storage property of the viscoelastic medium.

• Received 17 March 2021
• Revised 8 September 2021
• Accepted 13 September 2021
• Corrected 13 July 2022

DOI:https://doi.org/10.1103/PhysRevE.104.035207