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Physicists capture first images of atomic spin

By Ralph Hall,2014-03-04 20:45
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Physicists capture first images of atomic spin

Physicists capture first images of atomic spin [图片]

     The different shape and appearance of these individual cobalt atoms is caused by the different spin directions. Image courtesy of Saw-Wai Hla,

    Ohio University

    (PhysOrg.com) -- Though scientists argue that the emerging technology of spintronics may trump conventional electronics for building the next generation of faster, smaller, more efficient computers and high-tech

    devices, no one has actually seen the spina quantum mechanical property

    of electronsin individual atoms until now. In a study published as an Advance Online Publication in the journal Nature Nanotechnology on

    Sunday, physicists at Ohio University and the University of Hamburg in Germany present the first images of spin in action.

    The researchers used a custom-built microscope with an iron-coated tip

    to manipulate cobalt atoms on a plate of manganese. Through scanning

    tunneling microscopy, the team repositioned individual cobalt atoms on a surface that changed the direction of the electrons' spin. Images captured by the scientists showed that the atoms appeared as a single

    protrusion if the spin direction was upward, and as double protrusions with equal heights when the spin direction was downward.

    The study suggests that scientists can observe and manipulate spin, a finding that may impact future development of nanoscale magnetic storage, quantum computers and spintronic devices.

    "Different directions in spin can mean different states for data storage,"

    said Saw-Wai Hla, an associate professor of physics and astronomy in Ohio University's Nanoscale and Quantum Phenomena Institute and one of the primary investigators on the study. "The memory devices of current computers involve tens of thousands of atoms. In the future, we may be

    able to use one atom and change the power of the computer by the thousands."

    Unlike electronic devices, which give off heat, spintronic-based devices

    are expected to experience less power dissipation.

    The experiments were conducted in an ultra-high vacuum at the low

    temperature of 10 Kelvin, with the use of liquid helium. Researchers will

    need to observe the phenomenon at room temperature before it can be used in computer hard drives.

    But the new study suggests a path to that application, said study lead author Andre Kubetzka of the University of Hamburg. To image spin direction, the team not only used a new technique but also a manganese

    surface with a spin that, in turn, allowed the scientists to manipulate the spin of the cobalt atoms under study.

    "The combination of atom manipulation and spin sensitivity gives a new

    perspective of constructing atomic-scale structures and investigating

    their magnetic properties," Kubetzka said.

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