Yu, Salamon, and Lu reply

Plateaus Observed in the Field Profile of Thermal Conductivity in the Superconductor Bi 2 Sr 2 CaCu 2 O 8

“…A distinctive feature of the cuprates is that the in-plane thermal conductivity-K = K , , (measured with the gradient -TTll, in the plane) exhibits a large anomalous enhancelllellt (4, 5) below the critical temperature T,. Experilllellts (6,7) show that the anomaly is readily-suppressed by the magnetic field H. T h e origin of the anomaly, its field sensitivity-, and the response of the phonoll current are open questions.…”

Superconducting-state enhancement of thermal conductivity in the cuprates: Correlation with the pair density

“…Both phononic and electronic mechanisms have been proposed to explain this enhancement but there is currently no consensus regarding its origin. [2][3][4][5][6][7][8] A phononic explanation may be viewed as ''conventional'' in that for disordered superconductors such as Pb 0.9 Bi 0.1 , 9 NbC, 10 and Zr 70 Cu 30 , 11 a similar peak occurs, attributed to a reduction in phonon-carrier scattering as the charge carriers condense in the superconducting state. An electronic mechanism entails a dramatic enhancement in the quasiparticle lifetime, qp , in the superconducting state, so as to overcome a decreasing number of quasiparticle excitations.…”

“…In support of an electronic scenario are the microwave conductivity derived from the measured surface resistance, 12 which implies such an enhancement in qp , and theoretical models for the cuprates wherein scattering by spin fluctuations and d-wave pairing are central ingredients. 3,5,13 Though many measurements of ab for single-crystal specimens have been reported, a comparative survey of the enhancement systematics for different materials, and particularly its dependence on charge-carrier doping, has not been presented. In this paper we examine the available data for four compounds: YBa 2 Cu 3 O 6ϩx ͑Y-123͒, Bi 2 Sr 2 CaCu 2 O 8 ͑Bi-2212͒, Tl 2 Ba 2 CuO 6 ͑Tl-2201͒, and La 2Ϫx Sr x CuO 4 ͑LSCO͒.…”

Heat transport in the insulating phases of Sm1+x Ba2-x Cu3Oy high temperature superconductors

“…But the Sm 3+ ions substituting on Ba sites have a mass and ionic radius very close to that of Ba 2+ ions, thus they rather would not serve as effective point scatterers. Similarly, the oxygen vacancies may be regarded as small mass defects and should not significantly affect the thermal conductivity [14]. Concluding, taking into account only the κ e and κ ph contributions no spectacular differences between partner samples may be expected.…”