Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


First Report of Real-Time Manipulation and Control of Nuclear Spin Noise

Basel Physicists in collaboration with Dutch researchers have demonstrated a new method for polarizing nuclear spins in extremely small samples.

By Monitoring and controlling spin fluctuations, the method may provide a route for enhancing the resolution of magnetic resonance imaging (MRI) on the nanometer-scale, allowing researchers to make 3D images of smaller objects than ever before. The results have been published in the journal «Nature Physics».

Many of the elements that make up the matter around us, such as hydrogen or phosphorus, contain a magnetic nucleus at the center of each atom. This nucleus acts like a tiny magnet with a north and south pole. By applying a large magnetic field, the poles of these nuclei align along the magnetic field, producing a so-called nuclear spin polarization.

When the nuclei are irradiated with electromagnetic impulses (radio waves) at a very specific frequency, they change their direction away from the magnetic field. Because they are magnetic, the nuclei then start turning back. As they do so, they emit the energy they had previously absorbed through the radio waves. With a special antenna these signals can be detected.

This method is called nuclear magnetic resonance (NMR) and can provide very useful information about a sample, such as its chemical composition or structure. The method also forms the basis of magnetic resonance imaging (MRI), which can make 3D images of the density of an object and is often used on patients in hospitals.

However, for very small objects (i.e. smaller than a single cell) containing a small number of nuclei, the natural fluctuations of the nuclear spin polarization actually become larger than the polarization produced by a large magnetic field. These deviations are known as «spin noise». The fact that spin noise is so dominant at small scales is one of the reasons why measuring NMR and MRI in very small objects is so difficult.

Monitoring, controlling and capturing
The team led by Prof. Martino Poggio from the University of Basel in Switzerland has now demonstrated, together with scientists from Eindhoven University of Technology and Delft University of Technology in the Netherlands, a method for creating polarization order from such random fluctuations. By monitoring, controlling, and capturing statistical spin fluctuations, the team produced polarizations that were much larger than what can be created by applying a magnetic field.

This is the first report of the real-time manipulation, control, and capture of fluctuations arising from nuclear spin noise. The results are immediately relevant to recent technical advances that have dramatically reduced the possible detection volumes of NMR measurements. «Improved understanding of these phenomena may lead to new high resolution nano- and atomic-scale imaging techniques», explains Poggio, Argovia Nanotechnology Professor at the Swiss Nanoscience Institute. The Basel method may provide a route for enhancing the sensitivity of nanometer-scale magnetic resonance imaging (MRI) or possibly for the implementation of solid-state quantum computers.

Further Implications
The method’s ability to reduce nuclear spin polarization fluctuations may also be useful to enhance the coherence time of solid-state qubits. Qubits are units of quantum information used in quantum computers. Qubits implemented in the solid-state – especially in structures called quantum dots – are very susceptible to fluctuations in nuclear polarization: even tiny variations in the nuclear polarization destroy a qubit’s coherence. Therefore, the ability to control these fluctuations may extend qubit coherence times and thus help in the on-going development of solid-state quantum computers. Poggio points out that his «approach to capture and store spin fluctuations is generally applicable to any technique capable of detecting and addressing nanometer-scale volumes of nuclear spins in real-time».

The study was supported by the Canton Aargau, the Swiss National Science Foundation (SNF), the Swiss Nanoscience Institute (SNI), and the National Center of Competence in Research for Quantum Science and Technology (QSIT).

Original Citation
P. Peddibhotla, F. Xue, H. I. T. Hauge, S. Assali, E. P. A. M. Bakkers, M. Poggio
Harnessing nuclear spin polarization fluctuations in a semiconductor nanowire
Nature Physics (2013) | doi: 10.1038/nphys2731
Further Information
Prof. Martino Poggio, University of Basel, Department of Physics, Tel: +41 61 267 37 61, Mob: +41 79 452 81 97, E-Mail:

Christoph Dieffenbacher | Universität Basel
Further information:

More articles from Physics and Astronomy:

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>