14 1 Forward Through Backwards Time by RocketBoom
Thermodynamic Computing 1 14 Forward Through Backwards Time by - - PowerPoint PPT Presentation
Thermodynamic Computing 1 14 Forward Through Backwards Time by - - PowerPoint PPT Presentation
Thermodynamic Computing 1 14 Forward Through Backwards Time by RocketBoom The 2nd Law of Thermodynamics Total Entropy Clausius inequality S total 0 increases (1865) as time progresses R.Penrose (2010) Cycles of time Once or
Gavin E. Crooks Cycles of time R.Penrose (2010)
The 2nd Law of Thermodynamics
Clausius inequality (1865)
Total Entropy increases as time progresses
∆Stotal ≥ 0
Once or twice I have been provoked and asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold. It was also negative. Yet I was asking something which is about the scientific equivalent of “Have you read a work of Shakespeare's?”
- - C. P. Snow
Gavin E. Crooks
Thermodynamic Equilibrium: Future, past and present are indistinguishable
No change in entropy
Gavin E. Crooks
1 kT = 25 meV = 2.5 kJ/mol 1 natural unit of entropy equivalent to 1 kT of thermal energy T : Temperature (ambient 300 Kelvin) k : Boltzmann’s constant
What is Entropy?
average kinetic energy = 1.5 kT
Gavin E. Crooks
Trap Bead Actuator Bead Pizeoelectic Actuator Laser Trap Trap Bead Actuator Bead RNA Hairpin
probability
∆Stotal = 1 T
- W − ∆F
- temperature
work total entropy change free energy change force length u n f
- l
d i n g f
- l
d i n g unfolding Entropy sometimes goes down!
Unfolding of RNA hairpins. (circa 2000)
Gavin E. Crooks
The (improved) 2nd Law of Thermodynamics
Clausius inequality (1865)
he−∆Stotali = 1
Jarzynski identity (1997)
h∆Stotali 0
∆Stotal = 1 T
- W − ∆F
- equality only for
reversible process equality far-from-equilibrium
Gavin E. Crooks
Free Energy Change Work Inverse Temperature Forward Trajectory Reverse Trajectory Time Phase Space
Fluctuation Theorems: Dissipation breaks time-reversal symmetry
Gavin E. Crooks
What have we learned?
- There are exact, general relations valid far-from-equilibrium
- Trajectories are the primary objects (rather than states)
- The fluctuations matter
- Entropy change breaks time quantitatively reversal symmetry
- Directly relevant at small dissipation
- Information and entropy are related:
Information flow is as important as work and heat flow.
he−∆Stotali = 1
Gavin E. Crooks
Position (μm) 10
a b e f c d
5 10 5 10 5 10 5 0.5 −0.5 0.5 −0.5 0.5 −0.5 0.5 −0.5 0.5 −0.5 0.5 −0.5 10 5 10 5 Potential (kT) Position (μm)
Bits are physical
Experimental verification of Landauer’s principle linking information and thermodynamics
Antoine Be ´rut1, Artak Arakelyan1, Artyom Petrosyan1, Sergio Ciliberto1, Raoul Dillenschneider2 & Eric Lutz3{
Erasing 1 bit of information requires at least ln 2 kT energy Thermodynamic entropy and Shannon information are related
Non-equilibrium Theory of erasure see: Esposito (2011)
(2012)
Gavin E. Crooks
Experimental verification of Landauer’s principle linking information and thermodynamics
Antoine Be ´rut1, Artak Arakelyan1, Artyom Petrosyan1, Sergio Ciliberto1, Raoul Dillenschneider2 & Eric Lutz3{
Erasure time Average heat
4 3 2 1 10 20 30 40 〈Q〉 (kT)
c
τ (s)
But: Thermodynamically reversible computation requires Carnot limit, i.e. infinity long time
Gavin E. Crooks
Experimental verification of Landauer’s principle linking information and thermodynamics
Antoine Be ´rut1, Artak Arakelyan1, Artyom Petrosyan1, Sergio Ciliberto1, Raoul Dillenschneider2 & Eric Lutz3{
Heat P(Heat) Fluctuations matter! Tradeoff between error, time, and energy
0.15 0.10 0.05 P(Q) Fmax (10−14 N) −2 2 4 Q (kT)
b
Gavin E. Crooks
Feedback Fluctuation Theorems (c2010)
D e− 1
T (W −∆F )−IE
= 1
Demon-system information
Sagawa & Ueda (2008) Horowitz & Vaikuntanathan (2010)
Research Highlights
Gavin E. Crooks
Research Highlights Thermodynamics of Prediction Still, Sivak, Bell, Crooks (2012)
Gavin E. Crooks / 22 14
Research Highlights 1/2
Optimal thermodynamic control Coupled Systems Experiments
Feynman's ratchet
Bang et al (2018)
Gavin E. Crooks Lahiri, Sohl-Dickstein, Ganguli (2016)
time-dissipation-error tradeoff Thermodynamics uncertainty realtions Self-organization and the generation of complexity
Research Highlights 2/2
- T. R. Gingrich, J. M. Horowitz, N. Perunov
and J. L. England (2015)
Gavin E. Crooks / 22 16