Strongly enhanced superconductivity in coupled t-J segments

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Contributors

  • Sahinur Reja - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Jeroen Van Den Brink - , Chair of Solid State Theory, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Satoshi Nishimoto - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)

Abstract

The t-J Hamiltonian is one of the cornerstones in the theoretical study of strongly correlated copper-oxide based materials. Using the density-matrix renormalization group method we obtain the phase diagram of the one-dimensional t-J chain in the presence of a periodic hopping modulation, as a prototype of coupled-segment models. While in the uniform 1D t-J model the near half-filling superconducting state dominates only at unphysically large values of the exchange coupling constant J/t>3; we show that a small hopping and exchange modulation very strongly reduces the critical coupling to be as low as J/t∼1/3 - well within the physical regime. The phase diagram as a function of the electron filling also exhibits metallic, insulating line phases and regions of phase separation. We suggest that a superconducting state is easily stabilized if t-J segments creating local spin-singlet pairing are coupled to each other - another example is the ladder system.

Details

Original languageEnglish
Article number067002
JournalPhysical review letters
Volume116
Issue number6
Publication statusPublished - 10 Feb 2016
Peer-reviewedYes

Keywords

ASJC Scopus subject areas