DIEP seminar by Deepak Gupta
Designing low-dissipation control driving protocols (optimal protocols) for small-scale systems (length-scale: ~nanometer—micrometer), where thermal fluctuations play a significant role, is an active field of research. This field has attracted researchers from various scientific disciplines, including Physics, Chemistry, Biology, and Mathematics. A driving protocol refers to a procedure by which a system is driven from one configuration in its state space to another. For example, unzipping a DNA hairpin from a zippedconfiguration or vice versa . In this talk, Deepak will specifically discuss designing efficient driving procedures for two different systems: 1) A biomolecular motor—the F1ATPase, and 2) an active Ornstein-Uhlenbeck particle .
In general, designing such protocols is challenging due to the spatial nonlinearity of the systems and the presence of environmental thermal fluctuations. Nonetheless, a near-equilibrium (linear response ) framework is found to apply to a broad class of small-scale systems. He will follow this framework to design non-trivial protocols to drive the F1's γ-shaft to synthesize ATP at low-dissipation cost. Further, this near-equilibrium framework5 will be applied to construct the driving protocols for an active Ornstein-Uhlenbeck particle to drive this particle over a non-linear spatial potential energy landscape. (Notice that this particle is in a non-equilibrium stationary state at a fixed control parameter.) For both cases, the analysis reveals that the designed protocols, based on the linear response (or close-to-equilibrium) approach, dissipate lower energy as compared to the constant velocity driving protocol for a wide range of protocol durations.
In the second part of his talk, Deepak will show his recent experimental results on F1ATPase motor, where they compared the dissipation of driving this motor using two experimentally viable protocols: angle clamp and torque clamp. The experimental results (supported by analytical findings) suggest that angle clamp driving requires less work than that of the torque clamp
Deepak is a Humboldt Fellow at Institut für Physik und Astronomie, Technische Universität Berlin.
If you wish to attend this seminar online, please send an email to r.lier@uva.nl to receive the zoom-link.