Theoretical Sciences Unit Seminar

JNCASR
Kanada Auditorium

This is an announcement for the Theoretical Sciences Unit's Seminar on 26th September 2022 (Monday).

 

Title:  Identifying structural signature of dynamical heterogeneity via the local softness parameter

Speaker: Dr. Sarika Maitra Bhattacharyya

Affiliation: Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune

Date and Time:  26th September 2022 (Monday) Time: 11:00 AM Tea/Coffee: 10:45 AM

Venue: Kanada Auditorium, JNCASR

 

Title:  Identifying structural signature of dynamical heterogeneity via the local softness parameter

 

Abstract:

The origin of dynamic heterogeneity (DH) in supercooled liquids is a topic of

intense research [1-3]. It is often suggested that in analogy with crystals, in

supercooled liquids structural defects are present giving rise to the DH.

However, identifying structural defects in a supercooled liquid is a nontrivial

task [4]. We use the softness of a mean field caging potential developed by

us earlier [5,6] as an order parameter and show that this softness parameter

can capture the structural heterogeneity, and its lifetime is similar to the lifetime

of the cage [7]. We also predict that the local softness and the local dynamics

are causal and with the decrease in temperature, the correlation between

structure and dynamics increases. The study shows that at lower

temperatures, the structural heterogeneity increases, and since the structure

becomes a better predictor of the dynamics, it leads to an increase in the

DH.

[1] A. Widmer-Cooper, H. Perry, P. Harowell, and D. Reichman, Nat. Phys. 4, 711 (2016).

[2] S. S. Schoenholz, E. D. Cubuk, and D. Sussman et al., Nat. Phys. 12, 469 (2016); F. P. Landes, G. Biroli,

O. Dauchot, A. J. Liu, and D. R. Reichman, Phys. Rev. E 101, 010602 (2020).

[3] G. Kapteijns et al., J. Chem. Phys. 155, 074502 (2021)

[4] D. Wei et al., J. Chem. Phys. 150, 114502 (2019).

[2] M. K. Nandi, A. Banerjee, C. Dasgupta and S.M. Bhattacharyya Phys. Rev. Lett., 119, 265502 (2017)

[6] M. K. Nandi and S. M. Bhattacharyya , Phys. Rev. Lett.126, 208001 (2021).

[7] M. Sharma, M. K. Nandi, S. M. Bhattacharyya Phys. Rev. E 105, 044604 (2022).

Prof. Srikanth Sastry