Experimental probing of the anisotropy of the empty p states near the Fermi level in MgB2

TL;DR

This study uses electron energy loss spectroscopy to experimentally analyze the anisotropy of empty p states near the Fermi level in MgB2, confirming theoretical predictions about their orbital character.

Contribution

It provides the first experimental angular-resolved measurement of the anisotropic p states at the Fermi level in MgB2 using EELS.

Findings

Empty p states at the Fermi level have pxy character.

States are anisotropic and confirmed by angular-resolved EELS.

Results agree with first-principle calculations.

Abstract

We have studied the Boron K-edge in the superconductor MgB2 by electron energy loss spectroscopy (EELS) and experimentally resolved the empty p states at the Fermi level that have previously been observed within an energy window of 0.8eV by soft x-ray absorption spectroscopy. Using angular resolved EELS, we find that these states at the immediate edge onset have pxy character in agreement with predictions from first-principle electronic structure calculations.