Condensed Matter Physics Seminar

2 p.m., Thursday, March 11, 2004
Room 1201, Physics Building

Noise spectroscopy of a single spin

Alexander V. Balatsky

(Los Alamos National Laboratory)

Abstract: Recent scanning tunneling microscope (STM) experiments on magnetic centers on a surface demonstrate that one can get a spatially localized current signal directly related to a precessing spin. I will discuss possible mechanisms that allows tunneling current couple to the spin degrees of freedom. Important feature of these experiments is that signal is observed in the noise of the tunneling current. I will argue that this experiment is another example, among many, of the noise spectroscopy. A possible extension of this technique where one considers the coupling between ac Josephson current and a single spin in the junction is proposed [1]. I will argue that in an external magnetic field, resulting in a Larmor precession of a spin, spin is nutating at the Josephson frequency. Sidebands at sum and difference of Larmor and Josephson frequencies are formed. Noise spectroscopy is an emergent technique that might be applied to surface magnetism studies and to quantum information.

[1] Jian-Xin Zhu, Z. Nussinov, A. Shnirman and A. V. Balatsky, "Novel Spin Dynamics in a Josephson Junction", PRL to be published, cond-mat/0306710.

Host: Yakovenko
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