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arXiv · 2308.13846

Phonon-Mediated Quasiparticle Lifetime Renormalizations in Few-Layer Hexagonal Boron Nitride

Håkon I. Røst·Simon P. Cooil·Anna Cecilie Åsland·Jinbang Hu·Ayaz Ali·Takashi Taniguchi·Kenji Watanabe·Branson D. Belle·Bodil Holst·Jerzy T. Sadowski·Federico Mazzola·Justin W. Wells
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Abstract

Understanding the collective behavior of the quasiparticles in solid-state systems underpins the field of non-volatile electronics, including the opportunity to control many-body effects for well-desired physical phenomena and their applications. Hexagonal boron nitride (hBN) is a wide energy bandgap semiconductor, showing immense potential as a platform for low-dimensional device heterostructures. It is an inert dielectric used for gated devices, having a negligible orbital hybridization when placed in contact with other systems. Despite its inertness, we discover a large electron mass enhancement in few-layer hBN affecting the lifetime of the $\pi$-band states. We show that the renormalization is phonon-mediated and consistent with both single- and multiple-phonon scattering events. Our findings thus unveil a so-far unknown many-body state in a wide-bandgap insulator, having important implications for devices using hBN as one of their building blocks.

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Håkon I. Røst, Simon P. Cooil, Anna Cecilie Åsland, Jinbang Hu, Ayaz Ali, Takashi Taniguchi, Kenji Watanabe, Branson D. Belle, Bodil Holst, Jerzy T. Sadowski, Federico Mazzola, Justin W. Wells. 2023-08-26. Phonon-Mediated Quasiparticle Lifetime Renormalizations in Few-Layer Hexagonal Boron Nitride. https://doi.org/10.1021/acs.nanolett.3c02086

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