Structural properties and electronic structures of amorphous HfO$_{2}$/Si(001) interface

Using the projector augmented wave method within the generalized gradient approximation, we have performed \textit{ab-initio }molecular dynamics simulations to generate an atomic structure model of amorphous hafnium dioxide ($a$-HfO$_{2})$ by a melt-and-quench scheme, and have investigated the structural and electronic properties of $a$-HfO$_{2}$ /Si(001)-$c$(2$\times $2) interface. The structure of $a$-HfO$_{2}$ sample is analyzed via atomic coordination number and partial pair-radius distribution functions. Our results show the average Hf-O nearest-neighbor distance is 2.06 ?, which is comparable with the Hf-O bond lengths (in the range from 2.04? $\sim $ to 2.25?) in monoclinic HfO$_{2}$ crystalline, and also indicate the generated sample essentially reflects the experimentally measured structural characteristics of $a$-HfO$_{2}$. Most importantly, it is found that the valence band offset of $a$-HfO$_{2}$/Si interface is about 2.97eV, and our results suggest that the coordination of Si atoms at interface would significantly affect the electronic properties of interface.