Physics at Virginia

"Phononics in liquids and supercritical fluids"

Dima Bolmatov , Brookhaven National Lab
[Host: Genya Kolomeisky]

Abstract: While physicists have a good theoretical understanding of the heat capacity of both solids and gases, a general theory of the heat capacity of liquids has always remained elusive. Apart from being an awkward hole in our knowledge of condensed-matter physics, heat capacity – the amount of heat needed to change a substance's temperature by a certain amount – is a technologically relevant quantity that it would be nice to be able to predict1. I will introduce a phonon-based approach to liquids2 and supercritical fluids3, and describe its thermodynamics in terms of phonon excitations. I will show that the effective Hamiltonian4 has a transverse phononic gaps and explain their evolution with temperature variations. I will explain how the introduced formalism covers the Debye theory of solids, the phonon theory of liquids, and thermodynamic limits such as the Delong-Petit and the ideal gas thermodynamic limits. The experimental evidence for the new thermodynamic boundary (the Frenkel line) on the pressure-temperature phase diagram will be demonstrated5. Finally, I will discuss the phonon propagation and localization effects in liquids above and below the Frenkel line, and outline new directions towards phonon band gaps engineering and sound manipulation.

Condensed Matter Seminar
Thursday, October 15, 2015
11:00 AM
Physics Building, Room 313
Note special time.
Note special room.

 Add to your calendar

To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Condensed Matter Seminars), date, name of the speaker, title of talk, and an abstract (if available).