Kryuchkov Nikita P, Mistryukova Lukiya A, Sapelkin Andrei V, Brazhkin Vadim V, Yurchenko Stanislav O
Bauman Moscow State Technical University, 2nd Baumanskaya street 5, Moscow 105005, Russia.
School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, England.
Phys Rev Lett. 2020 Sep 18;125(12):125501. doi: 10.1103/PhysRevLett.125.125501.
The change in dispersion of high-frequency excitations in fluids, from an oscillating solidlike to a monotonic gaslike one, is shown for the first time to affect thermal behavior of heat capacity and the q-gap width in reciprocal space. With in silico study of liquified noble gases, liquid iron, liquid mercury, and model fluids, we established universal bilinear dependence of heat capacity on q-gap width, whereas the crossover precisely corresponds to the change in the excitation spectra. The results open novel prospects for studies of various fluids, from simple to molecular liquids and melts.
