Tunneling spectroscopy of the electron exchange-correlation interaction in a Schottky barrier in a quantizing magnetic field: $n$-GaAs/Me junctions

The magnetic-field-induced variation in the width of an anomalous resistance peak in the region of a zero-bias anomaly in $n$-GaAS/Me tunnel junctions was studied in the range of magnetic field strengths of up to $23$ T at the temperatures $T=4.2$ and $1.5$ K. The experimental curves depend neither on the method of a semiconductor substrate surface preparation (doped single crystal cut or epitaxially grown doped semiconductor film) nor on the type of dopant (Te, Si) and metal (Me=Au, Al). A comparison to a theoretical dependence of the exchange potential on the magnetic field strength for electrons on the lowest Landau level confirms that the anomalous resistance peak width can serve as a measure of the exchange-correlation potential jump on the surface of the degenerate electron gas. The results provide an explanation for the dependence of the zero-bias anomaly on the magnetic field and offer a possibility for directly measuring the electron exchange-correlation interaction in a Schottky barrier by means of tunneling spectroscopy.