Thermal conductivity and competing orders in d-wave superconductors

We derive the expression for the thermal conductivity κ in the low-temperature limit T → 0 in d-wave superconductors, taking into account the presence of competing orders such as spin-density wave, is-pairing, etc. . The expression is used for analyzing recent experimental data in La2−xSrxCuO4. Our analysis strongly suggests that competing orders can be responsible for anomalies in behavior of thermal conductivity observed in those experiments. PACS. 74.25.Fy Transport properties (electric and thermal conductivity, thermoelectric effects, etc.) – 74.72.Dn La-based cuprates – 74.72.-h Cuprate superconductors (high-Tc and insulating parent compounds) The existence of four nodal points in d-wave superconductors provides rich and, sometimes, controllable dynamics of quasiparticle excitations at zero temperature. In particular, the expressions for electrical, thermal, and spin conductivity simplify considerably in the universallimit ω → 0, T → 0 [1,2]. It is noticeable that the role of the thermal conductivity κ is special: while vertex and/or Fermi-liquid corrections modify the bare, ”universal”, values of both electric and spin conductivities, the universal value of the thermal conductivity is not influenced by them [2]. It is: κ0 T = k B