Статья

Distinct pairing symmetries in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>Nd</mml:mi><mml:mn>1.85</mml:mn></mml:msub><mml:msub><mml:mi>Ce</mml:mi><mml:mn>0.15</mml:mn></mml:msub><mml:msub><mml:mi>CuO</mml:mi><mml:mrow><mml:mn>4</mml:mn><mml:mo>−</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>La</mml:mi><mml:mn>1.89</mml:mn></mml:msub><mml:msub><mml:mi>Sr</mml:mi><mml:mn>0.11</mml:mn></mml:msub><mml:msub><mml:mi>CuO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>single crystals: Evidence from comparative tunneling measurements

L. ShanNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaYuan HuangNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaHongjun GaoNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaYetang WangNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaShiliang LiDepartment of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USAPengcheng DaiCenter for Neutron Scattering, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USAFuwei ZhouNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaJian XiongNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaW. X. TiNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, ChinaH. H. WenNational Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, China

2005lv

ABI

Аннотация

We used point-contact tunneling spectroscopy to study the superconducting pairing symmetry of electron-doped ${\mathrm{Nd}}_{1.85}{\mathrm{Ce}}_{0.15}{\mathrm{CuO}}_{4\ensuremath{-}y}$ (NCCO) and hole-doped ${\mathrm{La}}_{1.89}{\mathrm{Sr}}_{0.11}{\mathrm{CuO}}_{4}$ (LSCO). Nearly identical spectra without zero bias conductance peak (ZBCP) were obtained on the (110) and (100) oriented surfaces (the so-called nodal and anti-nodal directions) of NCCO. In contrast, LSCO showed a remarkable ZBCP in the nodal direction as expected from a $d$-wave superconductor. Detailed analysis reveals an $s$-wave component in the pairing symmetry of the NCCO sample with $\ensuremath{\Delta}∕{k}_{B}{T}_{c}=1.66$, a value remarkably close to that of a weakly coupled Bardeen-Cooper-Schriffer (BCS) superconductor. We argue that this $s$-wave component is formed at the Fermi surface pockets centered at $(\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi},0)$ and $(0,\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi})$ although a $d$-wave component may also exist.

Перевод пока недоступен

Идентификаторы

DOI: 10.1103/physrevb.72.144506

Цитирования и источники

Цитирований: 3Использованных источников: 0

Показатели — AkademScholar