Spin Noise Fluctuations from Paramagnetic Molecular Adsorbates on Surfaces

Abstract

The measurement of spin noise in nuclei was pioneered on bulk samples more than two decades ago. An ensemble of spins can produce a coherent signal at the frequency of a static magnetic field, known as spin noise, an effect due to the statistical polarization of small ensembles. The difficulty of these measurements is that the signal is extremely small, even if electron spins are detected. Although the statistical polarization of N spins dominates the Boltzmann statistics if N approaches unity, a more sensitive tool is requested to measure the polarization of the magnetic moment of a single spin. In this paper we report on the verification of recent results on the detection of spin noise from paramagnetic molecules of BDPA alpha,gamma,Bisdiphenylene,betha,phenylallyl by Durkan and coworkers. C. Durkan and M. E. Welland, Appl. Phys. Lett. 80, 458 2002 We also present new results on a second paramagnetic specie, DPPH (1,1,Diphenyl,2.picrylhydrazyl), deposited on Au(111) surfaces. ESR spectra from ultrathin films of DPPH and BDPA grown on Au(111) are reported. We prove that the paramagnetic molecules preserve their magnetism on the surface. These data and a thorough analysis of the signal recovery apparatus help to understand the low statistical recurrence of the spin noise in the data set . A thorough description of the experimental apparatus together with an analysis of the parameters that determine the sensitivity are also presented.

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• Dynamical spin-electric coupling in a quantum dot
• Interference effects in resonant magneto-transport
• Quantum Electronic Transport through a Precessing Spin
• Spectrum of qubit oscillations from Bloch equations
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• Noise spectroscopy of a single spin with spin polarized STM
• Tunneling measurement of quantum spin oscillations
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• Low-frequency noise in tunneling through a single spin
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Cited by in corpus (6)

• Single-molecule Scale Magnetic Resonance Spectroscopy using Nitrogen-Vacancy Centers in Diamond
• "Listening" to the spin noise of conduction electrons in bulk n:GaAs
• Electron Paramagnetic Resonance of Single Magnetic Moment on a Surface
• A model for the ESR-STM phenomenon
• Stable $\pi$-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) adsorbed at the elbows of $22\times \sqrt{3}$ reconstructed Au(111)
• Nanoscopic interferometer model for spin resonance in current noise