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arXiv · 2108.05860

Coherent phonon transport and minimum of thermal conductivity in LaMnO$_3$/SrMnO$_3$ superlattices

Dennis Meyer·Daniel Metternich·Pia Henning·Jan Philipp Bange·Robert Gruhl·Vitaly Bruchmann-Bamberg·Vasily Moshnyaga·Henning Ulrichs
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Abstract

In this Letter, we present investigations of thermal transport in (LaMnO$_3$)$_n$/(SrMnO$_3$)$_n$ superlattices (SLs) with SL periods $\Lambda=2n$ between $2$ and $12$ unit cells. The analysis of the experimental data clearly reveals a minimum in the thermal conductivity $\kappa$ at $\Lambda=6$ u.c. Furthermore, we theoretically estimate the phonon mean free path to be about $3\Lambda$ in our SLs. These findings clearly show that, in a wide temperature range of $\pm 100\,$K around room temperature, thermal transport in our manganite SLs is coherent. In addition, we demonstrate that antiferromagnetic magnetic ordering can control the degree of coherency. This opens the challenging perspective for active control of coherent transport in correlated matter.

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Dennis Meyer, Daniel Metternich, Pia Henning, Jan Philipp Bange, Robert Gruhl, Vitaly Bruchmann-Bamberg, Vasily Moshnyaga, Henning Ulrichs. 2021-08-12. Coherent phonon transport and minimum of thermal conductivity in LaMnO$_3$/SrMnO$_3$ superlattices. https://arxiv.org/abs/2108.05860

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