Observation of second sound in graphite at temperatures up to 100 K
ORAL
Abstract
Wavelike thermal transport in solids, referred to as second sound, has until now been an exotic phenomenon limited to a handful of materials at low temperatures. This has restricted interest in its occurrence and in its potential applications. Through time-resolved optical measurements of thermal transport on 5-20 μm length scales in graphite, we have made direct observations of second sound at temperatures above 100 K. The results are in qualitative agreement with ab initio calculations that predict wavelike phonon hydrodynamics on ~ 1-μm length scale up to almost room temperature. The results suggest an important role of second sound in microscale transient heat transport in two-dimensional and layered materials in a wide temperature range.
*S.H., V.C., Z.D., and G.C. acknowledge support from the office of Naval Research (MURI grant N00014-16-1-2436) and from the Solid State Solar-Thermal Energy Conversion Center (S3TEC), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (Award DE-SC0001299). R.A.D., A.A.M., and K.A.N. acknowledge support from the U.S. National Science Foundation (EFRI-2-DARE Award No. 1542864).
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Presenters
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Ryan Duncan
- Massachusetts Institute of Technology