Oscillations of the magnetic polarization in a Kondo impurity at finite magnetic fields

TL;DR

This paper investigates how a magnetic field affects the electronic and magnetic properties of a Kondo impurity, revealing oscillations in magnetic polarization and unmasking the Kondo cloud without altering charge distribution.

Contribution

It demonstrates that a magnetic field reveals the Kondo cloud and induces oscillating magnetic polarization, providing new insights into the impurity's internal electronic structure.

Findings

Magnetic field unmasks the Kondo cloud.

Oscillating magnetic polarization with half Fermi wavelength period.

No change in charge distribution due to magnetic field.

Abstract

The electronic properties of a Kondo impurity are investigated in a magnetic field using linear response theory. The distribution of electrical charge and magnetic polarization are calculated in real space. The (small) magnetic field does not change the charge distribution. However, it unmasks the Kondo cloud. The (equal) weight of the d-electron components with their magnetic moment up and down is shifted and the compensating s-electron clouds don't cancel any longer (a requirement for an experimental detection of the Kondo cloud). In addition to the net magnetic polarization of the conduction electrons an oscillating magnetic polarization with a period of half the Fermi wave length is observed. However, this oscillating magnetic polarization does not show the long range behavior of Rudermann-Kittel-Kasuya-Yosida oscillations because the oscillations don't extend beyond the Kondo radius. They represent an internal electronic structure of the Kondo impurity in a magnetic field. PACS: 75.20.Hr, 71.23.An, 71.27.+a