Charge manipulation and imaging of the Mn acceptor state in GaAs by Cross-sectional Scanning Tunneling Microscopy

TL;DR

This study uses cross-sectional scanning tunneling microscopy to visualize and analyze the anisotropic shape of individual Mn acceptor states in GaAs, revealing insights into their electronic structure at room temperature.

Contribution

It provides the first direct imaging of Mn acceptor states in GaAs and attributes their anisotropic shape to a d-wave component in the wave-function.

Findings

Mn acceptor states exhibit a cross-like anisotropic shape

The acceptor state is linked to a valence hole bound to Mn

The anisotropy is due to a d-wave component in the wave-function

Abstract

An individual Mn acceptor in GaAs is mapped by Cross-sectional Scanning Tunneling Microscopy (X-STM) at room temperature and a strongly anisotropic shape of the acceptor state is observed. An acceptor state manifests itself as a cross-like feature which we attribute to a valence hole weakly bound to the Mn ion forming the (Mn$^{2+}3d^5+hole$) complex. We propose that the observed anisotropy of the Mn acceptor wave-function is due to the d-wave present in the acceptor ground state.