Unifying explanation for carrier relaxation anomaly in gapped systems

Shota Ono; Hiroyuki Shima; Yasunori Toda

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arXiv · 1202.2635

Unifying explanation for carrier relaxation anomaly in gapped systems

Shota Ono·Hiroyuki Shima·Yasunori Toda

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Abstract

We develop a theory to describe energy relaxation of photo-excited carriers in low-temperature ordered states with band gap opening and formulate carrier relaxation time $\tau$ near and below transition temperature $T_{\mathrm{c}}$ by quantifying contributions from different carrier-phonon scatterings to the relaxation rate. The theory explains anomalous experimental observations of $\tau$ in gapped systems. Transverse acoustic (TA) phonon modes play a crucial role in carrier relaxation; their heat capacity determines $\tau$-divergence near $T_{\mathrm{c}}$. The theory is validated by fitting $\tau$ of fullerene polymers onto a theoretical curve.

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Shota Ono, Hiroyuki Shima, Yasunori Toda. 2012-02-13. Unifying explanation for carrier relaxation anomaly in gapped systems. https://arxiv.org/abs/1202.2635

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