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From Glass to Lorentz Gas

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Gelation. 4. t. c. At A3 singularity point. 2. Dynamic heterogeneities: MCT analysis ... 3. This model is a good model for gelation? (MCT description for gelation? ... – PowerPoint PPT presentation

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Title: From Glass to Lorentz Gas


1
From Glass to Lorentz Gas
Crossover of Slow Dynamics in Random Media
Kunimasa Miyazaki
Collaborators
Kang Kim and Shinji Saito (IMS)
(Japan-France 11/20/2008)
2
OVERVIEW
  • Introduction

1. Spatially /dynamically heterogeneous systems
2. Krakoviacks replica MCT
  • Slow dynamics of fluids in random matrices

1. Type A to Type B transition
2. Dynamic heterogeneities
3. Re-entrant transition?
  • Summary

3
INTRODUCTION
  • Slow dynamics in spatially/dynamically
    heterogeneous systems

Glasses
  • Slow dynamics with kinetic arrest
  • Spatially homogeneous but dynamically
  • inhomogeneous

(Weeks, 2000)
Colloidal Gels
  • Slow dynamics with kinetic arrest
  • Spatially and/or dynamically inhomogeneous

(Lu, 2008)
4
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Density
5
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Type B Sudden appearance of 2 step relaxation
Type A Continuous and 1 step relaxation
Density
6
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Type B Broad and high NEP escorted by
microscopic length scale
Type A Low NEP escorted by large length scale
Density
7
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Dynamic Heterogeneities
Glass Dynamic origin
Gel Static origin
Density
8
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Glasses
  • Slow dynamics with kinetic arrest
  • Spatially homogeneous but dynamically
  • inhomogeneous

(Weeks, 2000)
Colloidal Gels
  • Slow dynamics with kinetic arrest
  • Spatially and/or dynamically inhomogeneous

(Lu, 2008)
9
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
Glasses
  • Slow dynamics with kinetic arrest
  • Spatially homogeneous but dynamically
  • inhomogeneous

(Weeks, 2000)
Diffusing particles in random media
  • Slow dynamics with kinetic arrest
  • Spatially and/or dynamically inhomogeneous

10
INTRODUCTION
Slow dynamics in spatially/dynamically
heterogeneous systems
11
INTRODUCTION
Replica Mode Coupling Theory (Krakoviack, 2005,
2007)
12
INTRODUCTION
Replica Mode Coupling Theory (Krakoviack, 2005,
2007)
Glass phase
Fluid phase
13
INTRODUCTION
Replica Mode Coupling Theory (Krakoviack, 2005,
2007)
Correlation functions
Glass phase
Type B transition
Fluid phase
Type A transition
14
INTRODUCTION
Replica Mode Coupling Theory (Krakoviack, 2005,
2007)
Non-Ergodic Parameters
Glass phase
Type B transition
Fluid phase
Type A transition
15
INTRODUCTION
Replica Mode Coupling Theory (Krakoviack, 2005,
2007)
16
INTRODUCTION
1. Type A-Type B transition exists?
2. Dynamic heterogeneities?
3. Re-entrant transition really exists?
Is this a good minimal model for more complex
heterogeneous systems such as gels?
17
Slow Dynamics of Fluids in Random Matrices
MD simulation of soft binary and hard spheres
systems
3 dimension hard sphere system
Fluid particle density
Matrix particle density
Random matrix is made by quenching equilibrium
configurations
18
Slow Dynamics of Fluids in Random Matrices
1.Type A to Type B transition
19
Slow Dynamics of Fluids in Random Matrices
1. Type A to Type B transition Non-Ergodic
Parameters
20
Slow Dynamics of Fluids in Random Matrices
2. Dynamic heterogeneities
21
Slow Dynamics of Fluids in Random Matrices
2. Dynamic heterogeneities MCT analysis
Krakoviacks Replica MCT
F12 Schematic Model
22
Slow Dynamics of Fluids in Random Matrices
2. Dynamic heterogeneities MCT analysis
for a schematic model
(Franz and Parisi (2000) and Biroli, Bouchaud,
KM, Reichman (2006))
System under perturbation given by 2 point
correlation
Linear response for 2-point correlation
23
Slow Dynamics of Fluids in Random Matrices
2. Dynamic heterogeneities MCT analysis
Type A
Type B
24
Slow Dynamics of Fluids in Random Matrices
3. Re-entrant behavior
Other particles kick out the caged particle?
(Krakoviack)
?
25
Slow Dynamics of Fluids in Random Matrices
3. Re-entrant behavior
Other particles kick out the caged particle?
(Krakoviack)
?
26
Summary
More Questions than Answers
1. How dymamic length scales cross over to static
ones?
( should be analyzed using
and MCT)
2. Re-entrant transition really exist??
3. This model is a good model for gelation?
(MCT description for gelation?)
4. At least, the model is a good test bench for
the study of An singularities
27
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