Novel topological phase due to coexistence of superconductivity and spin-density wave: Application to high Tc superconductors

• A model for a coexistence phase between superconductivity (SC) and spin-density wave (SDW) is considered.
• The SC order parameter is taken as d+id symmetry and the SDW order parameter is taken as s  -wave as well as dxydxy symmetry.
• A new phase diagram consisting of a topologically non-trivial and trivial coexistence phase is obtained.
• The phase diagram is dictated by the amplitudes of both the order parameters.
• A possible experimental realization of the topological coexistence phase in the recent ARPES data of high-TcTc cuprates is discussed.

We consider a model of a coexistence phase between superconductivity(SC) and spin-density wave(SDW) where the SC is assumed to be of dx2−y2+idxy(d1+id2)dx2−y2+idxy(d1+id2) symmetry and the SDW order parameter is of s  -wave as well as dxydxy symmetry. The Hamiltonian having such a symmetry is shown to yield a novel topological coexistence phase in addition to the conventional one. It is shown that the amplitudes of both the order parameters determine a new phase diagram characterizing different topological phases. A possible experimental realization of such topological phases in a recent ARPES data of high TcTc superconductors in the extreme underdoped regime is analyzed by considering the effective order parameter to be a combination of dx2−y2dx2−y2 SC and dxy SDW.