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
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).
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