speaker: John Tranquada (BNL) host: Phil

When:
January 31, 2020 @ 1:30 pm – 2:30 pm

Intertwined Orders in Cuprate Superconductors

John Tranquada

Condensed Matter Physics & Materials Science Division

Brookhaven National Laboratory, Upton, NY 11973-5000

While the nature of cuprate superconductors remains controversial, the concept of intertwined orders provides a consistent way to understand multiple types of superconductivity in these hole-doped antiferromagnets [1].  Neutron and x-ray scattering experiments have demonstrated the tendency for the doped holes to segregate into stripes that are separated by locally-antiferromagnetic regions.  As originally proposed by Emery, Kivelson, and Zachar [2], the hole stripes can develop pairing correlations, but superconducting order is limited by the ability to establish phase order by Josephson coupling through the intervening magnetic regions.  When those intervening spin correlations can be gapped, spatially-uniform superconductivity can develop, where the coherent gap is limited by the spin gap [3].  When the spin-stripe correlations are strong, an alternative superconducting state involves a spatially-modulated pair wave function (pair density wave) intertwined with spin stripe order.  A sufficiently strong magnetic field destroys the superconducting order without disrupting the pair correlations within the stripes [4].

 

  1. E. Fradkin et al., Rev. Mod Phys. 87, 457 (2015).
  2. V. J. Emery et al., Phys. Rev. B 56, 6120 (1997).
  3. Yangmu Li et al., Phys. Rev. B 98, 224508 (2018).
  4. Yangmu Li et al., Sci. Adv. 5, eaav7686 (2019).

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