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\subsection{\texorpdfstring{Phosphorene \& Phosphorene Oxides}{Phosphorene  Phosphorene Oxides}}
\label{sec:phosphorene__phosphorene_oxides}


\url{https://en.wikipedia.org/wiki/Phosphorene} is a single layer of black phosphorous, recently
synthesized. blah blah...

\subsubsection{\texorpdfstring{Structural properties of phosphorene oxides}{Structural properties of phosphorene oxides}}
\label{sec:structural_properties_of_phosphorene_oxides}


Due to the existence of a lone pair of electrons on each P atom, 
phosphorene can be easily oxidized. At first, we have investigated 
the structural stability of PO\textsubscript{\emph{x}} with 0\textless \emph{x}\textless 1. 
For every given 0\textless \emph{x}\textless 1 of PO\textsubscript{\emph{x}}, diverse configurations 
are considered and optimized to find its equilibrium structure to know 
whether such a phosphorene oxide can be formed or not.



\subsubsection{\texorpdfstring{Strain effects on electronic properties of phosphorene oxides}{Strain effects on electronic properties of phosphorene oxides}}
\label{sec:strain_effects_on_electronic_properties_of_phosphorene_oxides}


As \emph{x} increases in PO\textsubscript{\emph{x}}, the electronic properties of
phosphorene oxides changes. We found an intriguing phenomenon that at
around 16\% uniaxial tensile strain, PO (with \emph{x}=1) becomes a metal
with a modified Dirac cone at the gamma point in its Brillouin zone.



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