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arXiv · 1603.00306

Revealing the ultrafast light-to-matter energy conversion before heat diffusion in a layered Dirac semimetal

Y. Ishida·H. Masuda·H. Sakai·S. Ishiwata·S. Shin
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Abstract

There is still no general consensus on how one can describe the out-of-equilibrium phenomena in matter induced by an ultrashort light pulse. We investigate the pulse-induced dynamics in a layered Dirac semimetal SrMnBi2 by pump-and-probe photoemission spectroscopy. At ~<1 ps, the electronic recovery slowed upon increasing the pump power. Such a bottleneck-type slowing is expected in a two-temperature model (TTM) scheme, although opposite trends have been observed to date in graphite and in cuprates. Subsequently, an unconventional power-law cooling took place at ~100 ps, indicating that spatial heat diffusion is still ill defined at ~100 ps. We identify that the successive dynamics before the emergence of heat diffusion is a canonical realization of a TTM scheme. Criteria for the applicability of the scheme is also provided.

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Y. Ishida, H. Masuda, H. Sakai, S. Ishiwata, S. Shin. 2016-03-01. Revealing the ultrafast light-to-matter energy conversion before heat diffusion in a layered Dirac semimetal. https://doi.org/10.1103/physrevb.93.100302

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