Volume 570 Issue 7761, 20 June 2019

Freedom of movement

In this week’s issue, Ichiro Takeuchi and his colleagues present evidence for the perfect transmission of electrons through a contact barrier between a normal metal and a topological superconductor. The work represents the observation of Klein tunnelling, a relativistic effect in which a particle can move through a barrier between two materials as if the barrier simply wasn’t there. Once an electron (gold sphere) has tunnelled through the barrier, it picks up a partner electron to form a Cooper pair (seen in the cover image at the far side of the tunnel). As a result, a negatively charged hole (black sphere) is reflected back from the barrier. Generally, there is some scattering of electrons at the barrier suppressing this process. But at the barrier with a topological superconductor, electron scattering is completely forbidden. Perfect electron tunnelling and the hole reflection therefore lead to exact doubling of the conductance, which the team’s results confirm. The researchers found that perfect transmission occurred regardless of the origin of the contact barrier and suggest that the finding could be useful in quantum information processing.

Cover image: Emily Edwards/Joint Quantum Institute

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Amendments & Corrections

  • Author Correction |

    • Joshi M. Ramanjulu
    • , G. Scott Pesiridis
    • , Jingsong Yang
    • , Nestor Concha
    • , Robert Singhaus
    • , Shu-Yun Zhang
    • , Jean-Luc Tran
    • , Patrick Moore
    • , Stephanie Lehmann
    • , H. Christian Eberl
    • , Marcel Muelbaier
    • , Jessica L. Schneck
    • , Jim Clemens
    • , Michael Adam
    • , John Mehlmann
    • , Joseph Romano
    • , Angel Morales
    • , James Kang
    • , Lara Leister
    • , Todd L. Graybill
    • , Adam K. Charnley
    • , Guosen Ye
    • , Neysa Nevins
    • , Kamelia Behnia
    • , Amaya I. Wolf
    • , Viera Kasparcova
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    • , Ana C. Puhl
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    • , Michael Klein
    • , Christopher B. Hopson
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    • , Marcus Bantscheff
    • , Giovanna Bergamini
    • , Michael A. Reilly
    • , Yiqian Lian
    • , Kevin J. Duffy
    • , Jerry Adams
    • , Kevin P. Foley
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    • , James Smothers
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    •  & John Bertin

Nature Index

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    Nature Index 2019 Annual tables

    The Nature Index 2019 Annual Tables highlights the institutions and countries which dominated research in the natural sciences in 2018.

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