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Physical review. B, Condensed matter

Spin and charge oscillations of a dot due to interaction with itinerant electrons

Yong-Jian Xiong, Shi‐Jie Xiong

Published Jun 12, 2001• 5 citations
Publisher

Abstract

We study the spin and charge oscillations of a quantum dot by exactly solving the time-dependent many-body Schr\"odinger equation of a system with a dot embedded in a ring. The dot is characterized by the on-site Coulomb interaction and the gate voltage that governs the occupation status. The itinerant electrons are moving in the ring. By switching on the coupling between the dot and the ring the spin and charge on the dot begin to have undamped oscillations. In the regime of single occupation of the dot, there exists a base frequency of the oscillations that is associated with the spin excitations. Some higher frequencies may be associated with both the charge and spin motions. The results reveal the dynamical characteristics of the spin and charge degrees of freedom and the spectrum of low-energy excitations.

DOI
10.1103/physrevb.64.033305

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We investigate the dynamics of spin and charge in an interacting system consisting of impurity and conduct-ing electrons. The time evolution of spin and charge in the impurity is given by solving the time-dependent Schroedinger equations for the many-body states of the interacting system. By switching on the interaction be-tween impurity and conducting electrons, the spin and charge of the impurity begin oscillations with frequencies that reflect the elementary excitations of the interacting system. The dynamics reflects the basic picture of the Kondo effect.
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