2007/04/30 by V. M. Matic, V M Matic, N. Dj. Lazarov +1
Physics and Astronomy · #Chain (unit) #Constant (computer programming) #Cuprate #Ising model #Phase (matter) #Physics of Superconductivity and Magnetism #Plateau (mathematics) #Superconductivity in MgB2 and Alloys #Theoretical and Computational Physics #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-8984/19/34/346230
published as J. Phys.: Condens. Matter 19 (2007) 346230 · 5 pages of text, 3 figures, corrected two typing errors: in paragraph 1 of page 2 "p(x)=0.94 - replaced by p(x)=0.094", in paragraph 2 of page 5 "2/3 - replaced by 2/5". Accepted for publication in Journal of Physics Condensed Matter in a revised form (one page added to provide some more informations on length distributions of CuO chains and some references added)
arxiv created 2007/07/05 · openalex publication_date 2007/07/31 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A model for the charge transfer mechanism in YBa 2 Cu 3 O 6+ x high- T c cuprate based on the critical chain length concept is proposed to account for the 60 and 90 K plateaus in the T c ( x ) dependence. It has been shown that, when the statistics of CuO chain formation was described in terms of the two-dimensional asymmetric next-to-nearest neighbor Ising (ASYNNNI) model, at any constant temperature below the top of ortho-II phase there exists a uniquely defined value of critical chain length l cr ( T ) that yields a constant doping p ( x )≈const over the regime of ortho-II phase (related to the 60 K plateau of T c ( x )), while the 90 K plateau coincides with the monotonically increasing p ( x ) over the optimal doping level p = 0.16 in the regime of the ortho-I phase. Short length chains ( l < l cr ( T )), together with the first l cr ( T )−2 holes in longer chains ( l ≥ l cr ( T )), are taken as not capable of attracting electrons from CuO 2 planes. It is shown that only a part (≈41%) of the remaining l − l cr ( T )+1 holes in the long chains can capture electrons. The results obtained indicate that the ASYNNNI model and two-plateau-like behavior of T c ( x ) in YBa 2 Cu 3 O 6+ x are closely connected.