A5060042191- Advanced Thermodynamics and Statistical Mechanics
- DNA Repair Mechanisms
- Nonlinear Dynamics and Pattern Formation
- Liquid Crystal Research Advancements
- Material Dynamics and Properties
- DNA and Nucleic Acid Chemistry
- Solidification and crystal growth phenomena
- Theoretical and Computational Physics
- Mechanical and Optical Resonators
- Genomics and Chromatin Dynamics
- Force Microscopy Techniques and Applications
- stochastic dynamics and bifurcation
- Advanced Control Systems Optimization
- Neural dynamics and brain function
- Statistical Mechanics and Entropy
- Orbital Angular Momentum in Optics
- Spectroscopy and Quantum Chemical Studies
- Bacterial Genetics and Biotechnology
- Quantum Mechanics and Applications
- Quantum Information and Cryptography
- Microfluidic and Bio-sensing Technologies
- thermodynamics and calorimetric analyses
- Surfactants and Colloidal Systems
- nanoparticles nucleation surface interactions
- Quantum Electrodynamics and Casimir Effect
Simon Fraser University
2014-2024
Kavli Institute for Theoretical Sciences
2017
Utrecht University
2017
University of Waterloo
2005
Laboratoire de Physique de l'ENS de Lyon
1997-1998
École Normale Supérieure de Lyon
1991-1993
Université Paris Cité
1989-1990
Laboratoire de physique des Solides
1989-1990
Université Paris-Sud
1989-1990
Fermi National Accelerator Laboratory
1987-1989
Images and force measurements taken by an atomic-force microscope (AFM) depend greatly on the properties of spring tip used to probe sample’s surface. In this article, we describe a simple, nondestructive procedure for measuring constant, resonant frequency, quality factor AFM cantilever effective radius curvature tip. Our uses itself does not require additional equipment.
We confirm Landauer's 1961 hypothesis that reducing the number of possible macroscopic states in a system by factor two requires work at least kT ln 2. Our experiment uses colloidal particle time-dependent, virtual potential created feedback trap to implement erasure operation. In control experiment, similar manipulations do not reduce can be done reversibly. Erasing information thus work. individual cycles, erase below Landauer limit, consistent with Jarzynski equality.
Feedback and control theory are important ideas that should form part of the education a physicist but rarely do. This tutorial essay aims to give enough formal elements satisfy experimentalist designing or running typical physics experiment theorist wishing understand its broader intellectual context. The level is generally simple, although more advanced methods also introduced. Several types applications discussed, as practical uses feedback extend far beyond simple regulation problems...
We study the thermodynamic cost associated with erasure of one bit information over a finite amount time. present general framework for minimizing average work required when full control system's microstates is possible. In addition to exact numerical results, we find simple bounds proportional variance microscopic distribution state bit. short-time limit, get closed expression minimum needed erase The optimal protocol can be up factor four smaller relative protocols constrained end in local...
Replication timing is a crucial aspect of genome regulation that strongly correlated with chromatin structure, gene expression, DNA repair, and evolution. determined by the replication origin firing, which involves activation MCM helicase complexes loaded at origins. Nonetheless, how such firing regulated remains mysterious. Here, we show number MCMs origins regulates timing. We for first time in vivo multiple are Because early have more loaded, they are, on average, likely to fire S phase....
In a directional solidification experiment on moving nematic-isotropic interface, we observe solitary modes propagating across the interface. We also Eckhaus instability. presence of modes, pattern-selection mechanism is dynamic.
We measure the threshold accelerations necessary to excite surface waves in a vertically vibrated fluid container (the Faraday instability). Under proper conditions, thresholds and onset wavelengths agree with recent theoretical predictions for laterally infinite, finite-depth filled viscous fluid. Experimentally, we show that by using viscous, non-polar fluid, finite-size effects of sidewalls contamination can be made negligible. also corrections are order h/L , where h is depth L size....
The implications of causality are captured by the Kramers–Kronig relations between real and imaginary parts a linear response function. In 1937, Bode derived similar relation magnitude (response gain) phase. Although an equality, Bode’s is effectively inequality. This difference explained using elementary examples traced back to delays in flow information within system formed physical object measurement apparatus.
We calculate analytically the stochastic thermodynamic properties of an isothermal Brownian engine driven by a duo time-periodic forces, including its Onsager coefficients, work each force, and corresponding entropy production. verify relations between different operational regimes, maximum power, efficiency, minimum dissipation, reproduce signature features efficiency. All these results are experimentally tested without adjustable parameters on colloidal system.Received 15 July...
According to Landauer's principle, erasing a memory requires an average work of at least $kT\ln2$ per bit. Recent experiments have confirmed this prediction for one-bit represented by symmetric double-well potential. Here, we present experimental study erasure encoded in asymmetric Using feedback trap, find that the erase can be less than $kT\ln2$. Surprisingly, protocols differ subtly give measurably different values asymptotic work, result explain showing one protocol is with respect time...
Significance The second law of thermodynamics states that the total entropy an isolated system is constant or increasing. This constrains laws physics, ruling out perpetual-motion machines convert heat to work without any side effect. At its heart, a statement about entropy, yet elusive concept: To date, it has not been directly measured but rather inferred from other quantities, such as integral specific over temperature. Here, by measuring required erase fraction bit information, we...
We study the finite-time erasure of a one-bit memory consisting one-dimensional double-well potential, with each well encoding macrostate. focus on setups that provide full control over form potential-energy landscape and derive protocols minimize average work needed to erase bit fixed amount time. allow for cases where only some information encoded in is erased. For systems required end up local equilibrium state, we calculate minimum explicitly, terms Boltzmann distribution corresponding...
Information-driven engines that rectify thermal fluctuations are a modern realization of the Maxwell-demon thought experiment. We introduce simple design based on heavy colloidal particle, held by an optical trap and immersed in water. Using carefully designed feedback loop, our experimental "information ratchet" takes advantage favorable "up" to lift weight against gravity, storing potential energy without doing external work. By optimizing ratchet for performance via theory, we find rate...
We report anomalous heating in a colloidal system, an experimental observation of the inverse Mpemba effect, where for two initial temperatures lower than temperature thermal bath, colder systems heats up faster when coupled to same bath. For overdamped, Brownian particle moving tilted double-well potential, we find nonmonotonic dependence times on system. Entropic effects make effect generically weaker-harder observe-than usual (anomalous cooling). also observe strong version heating, cold...
Information engines can convert thermal fluctuations of a bath at temperature T into work rates order k_{B}T per relaxation time the system. We show experimentally that such engines, when in contact with is out equilibrium, extract much more work. place heavy, micron-scale bead harmonic potential ratchets up to capture favorable fluctuations. Adding fluctuating electric field increases extraction ten times, limited only by strength applied field. Our results connect Maxwell's demon energy...
Origins of DNA replication are generally inefficient, with most firing in fewer than half cell cycles. However, neither the mechanism nor importance regulation origin efficiency is clear. In fission yeast, stochastic, leading us to hypothesize that inefficiency and stochasticity result a diffusible, rate-limiting activator. We show Hsk1-Dfp1 kinase (the yeast Cdc7-Dbf4 homologue) plays such role. Increasing or decreasing levels correspondingly increases decreases efficiency. Furthermore,...