  Fundamental insight into lattice dynamics and phonon transport is critical to
the efficient manipulation of heat flow, which is one of the appealing
thermophysical problems with enormous practical implications. Phosphorene, a
novel elemental two-dimensional (2D) semiconductor with high carrier mobility
and intrinsically large direct band gap, possesses fascinating chemical and
physical properties distinctively different from other 2D materials. The
rapidly growing applications of phosphorene in nano-/opto-electronics and
thermoelectrics call for fundamental understanding of the thermal transport
properties. In this study, based on the analysis of electronic structure and
lattice dynamics, we demonstrate the formation of resonant bonding in
phosphorene. Fundamental insight into the thermal transport in phosphorene is
provided by discussing the role of resonant bonding in driving long-range
interactions and strong phonon anharmonicity. We reveal that the strong phonon
anharmonicity is associated with the soft transverse optical (TO) phonon modes
and arises from the long-range interactions driven by the orbital governed
resonant bonding. Our study highlights the physical origin of the phonon
anharmonicity in phosphorene, and also provides new insights into phonon
transport from the view of orbital states, which would be of great significance
to the design and development of high-performance phosphorene based
nano-devices.
