Report

Observation of second sound in graphite at temperatures above 100 K

See allHide authors and affiliations

Science  14 Mar 2019:
eaav3548
DOI: 10.1126/science.aav3548

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Wavelike thermal transport in solids, referred to as second sound, is an exotic phenomenon previously limited to a handful of materials at low temperatures. The rare occurrence of this effect restricted its scientific and practical significance. We directly observed second sound in graphite at temperatures above 100 K using time-resolved optical measurements of thermal transport on the micrometer-length scale. Our experimental results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics. We believe these results potentially indicate an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range.

View Full Text