Commensurate spin dynamics in the superconducting state of an electron-doped cuprate superconductor.
We report neutron scattering studies on two single crystal samples of the electron-doped (n-type) superconducting (SC) cuprate Nd2-xCexCuO4 (x=0.15) with T(c)=18 and 25 K. Unlike the hole-doped (p-type) SC cuprates, where incommensurate magnetic fluctuations commonly exist, the n-type cuprate shows commensurate magnetic fluctuations at the tetragonal (1/2 1/2 0) reciprocal points both in the SC and in the normal state. A spin gap opens up when the n-type cuprate becomes SC, as in the optimally doped p-type La2-xSrxCuO4. The gap energy, however, increases gradually up to about 4 meV as T decreases from T(c) to 2 K, which contrasts with the spin pseudogap behavior with a T-independent gap energy in the SC state of p-type cuprates.
Yamada
K
K
Institute for Chemical Research, Kyoto University, Uji 611-0011, Japan. yamada@scl.kyoto-u.ac.jp
Kurahashi
K
K
Uefuji
T
T
Fujita
M
M
Park
S
S
Lee
S H
SH
Endoh
Y
Y