Nucleation and Growth
Run with BKL, T=1, H=-1 until stable
Flip H to 0.3: what happens?
Metastability: red "gas" does not condense into a "fluid".
- Increase H to 0.8: what happens?
Multiple nucleation centers. Slow growth of nuclei.
- At T=1, find ranges of metastability, single nucleation, multiple nucleation. Remember to use many sweeps per draw when things are slow!
- How does the single/multiple boundary move when you go to 500x500?
Discuss Critical Droplet Theory
- In CMDDoc::OnParamChange, call sim->SetTime(0.0) to restart clock.
- Plot time vs. H for T=1; does it grow like the prediction?
Measure the Critical Droplet Size vs. H
Add m_upRadius to dialog box (resource view, add textlabel, editbox, properites->IDC_UPRADIUS, member variable m_upRadius, double)
Add IsingSimulation::GetDynamics()
In CMDDoc::OnParamChange, set dialogBox.m_upRadius=0.0; if not zero afterward, call
sim->GetDynamics()->SetRadius(dialogBox.m_upRadius)
- Write SpinDynamics::SetRadius(double radius). Use S->Set(i,j,+-1) to make a circle of up-spins in the center of a down-spin environment. Call ResetLattice(S) afterward (to re-setup LOOKLOC in ContinuousTime).
The critical droplet size Rc is the size which half the time will shrink, half the time will grow.
Plot Rc vs. H at T=1. Should it depend on T? How much?
M(T) and
s(T) come into the definition of Rc, when defined carefully.
Statistical Mechanics: Entropy, Order Parameters, and Complexity,
now available at
Oxford University Press
(USA,
Europe).