STM NMR and nuclear spin noise (original) (raw)

Nuclear Spin Noise and STM Noise Spectroscopy

arXiv (Cornell University), 2006

We consider fluctuations of the electronic spin due to coupling to nuclear spin. Noise spectroscopy of an electronic spin can be revealed in the Scanning Tunnelling Microscope (STM). We argue that the noise spectroscopy of electronic spin can reveal the nuclear spin dynamics due to hyperfine coupling. Tunnelling current develops satellites of the main lines at Larmor frequency and at zero frequency due to hyperfine coupling. We also address the role of the rf field that is at or near the resonance with the nuclear hyperfine field. This approach is similar to Electron Nuclear Double Resonance (ENDOR), in that is allows one to detect nuclear spin dynamics indirectly through its effect on electronic spin.

Model for electron spin resonance in STM noise

Physical Review B, 2014

We propose a model to account for the observed ESR-like signal at the Larmor frequency in the current noise STM experiments identifying spin centers on various substrates. The theoretical understanding of this phenomenon, which allows for single spin detection on surfaces at room temperature, is not settled for the experimentally relevant case that the tip and substrate are not spin polarized. Our model is based on a direct tip-substrate tunneling in parallel with a current flowing via the spin states. We find a sharp signal at the Larmor frequency even at high temperatures, in good agreement with experimental data. We also evaluate the noise in presence of an ac field near resonance and predict splitting of the signal by the Rabi frequency.

Nuclear spin noise in NMR revisited

The Journal of chemical physics, 2015

The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparisons to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the spin-noise and frequency-shift tuning optima.

0 60 21 13 v 1 5 F eb 2 00 6 Nuclear Spin Noise and STM Noise Spectroscopy

2006

A. V. Balatsky, ∗ J. Fransson, 3, † D. Mozyrsky, ‡ and Yishay Manassen § Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA Department of Materials Science and Engineering, Royal Institute of Technology (KTH), SE-100 44 Stockholm, Sweden Physics Department, Uppsala University, Box 530, SE-751 21 Uppsala, Sweden Department of Physics and the Ilse Katz Center for Nanometer Scale Science and Technology, Ben Gurion University, Beer Sheva, 84105, Israel

Electron spin resonance-scanning tunneling microscopy

Advances in Physics, 2012

Electron Spin Resonance-Scanning Tunneling Microscopy (ESR-STM) is a rapidly developing surface-science technique that is sensitive to a single spin existing on or nearby a solid surface. The single spin is detected through elevated noise at the Larmor frequency that appears when the single spin participates in the tunneling process between the tip and the surface. In this review, experimental and theoretical works which have been performed up to date on ESR-STM are reviewed. The remaining experimental problems which have to be solved, possible approach to differentiate between different mechanisms and the future of ESR-STM are discussed.

Inelastic Electron Tunneling Spectroscopy of a Single Nuclear Spin

Physical Review Letters, 2011

Detection of a single nuclear spin constitutes an outstanding problem in different fields of physics such as quantum computing or magnetic imaging. Here we show that the energy levels of a single nuclear spin can be measured by means of inelastic electron tunneling spectroscopy (IETS). We consider two different systems, a magnetic adatom probed with STM and a single Bi dopant in a Silicon nanotransistor. We find that the hyperfine coupling opens new transport channels which can be resolved at experimentally accessible temperatures. Our simulations evince that IETS yield information about the occupation of the nuclear spin states, paving the way towards transportdetected single nuclear spin resonance.

Distinction of Nuclear Spin States with the Scanning Tunneling Microscope

Physical Review Letters, 2013

We demonstrate rotational excitation spectroscopy with the scanning tunneling microscope for physisorbed H 2 and its isotopes HD and D 2. The observed excitation energies are very close to the gas phase values and show the expected scaling with the moment of inertia. Since these energies are characteristic for the molecular nuclear spin states we are able to identify the para and ortho species of hydrogen and deuterium, respectively. We thereby demonstrate nuclear spin sensitivity with unprecedented spatial resolution.

ESR-STM of a single precessing spin: Detection of exchange-based spin noise

Physical Review B, 2002

Electron Spin resonance scanning tunneling microscopy ͑ESR-STM͒ is an emerging technique which is capable of detecting the precession of a single spin. We discuss the mechanism of ESR-STM based on a direct exchange coupling between the tunneling electrons and the local precessing spin S. We claim that since the number of tunneling electrons in a single precessing period is small (ϳ20), one may expect a net temporary polarization within this period that will couple via exchange interaction to the localized spin. This coupling will randomly modulate the tunneling barrier and create a dispersion in the tunneling current which is a product of a Larmor frequency component due to the precession of the single spin and the dispersion of the spin of the tunneling electrons. This noise component is spread over the whole frequency range for random white noise spin polarization of electrons. In the opposite case where the power spectrum of the spins of the tunneling electrons has a peak at zero frequency an elevated noise in the current at L will appear. We discuss the possible source of this spin polarization. We find that for relevant values of parameters the signal-to-noise ratio in the spectral characteristic is 2-4 and is comparable to the reported signal to noise ratio. 1,2 The magnitude of the current fluctuation is a relatively weak increaing function of the dc current and magnetic field. The linewidth produced by the back action effect of tunneling electrons on the precessing spin is also discussed.