Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2010 Jun 4;104(22):227002. doi: 10.1103/PhysRevLett.104.227002. Epub 2010 Jun 2.
We have examined the relaxation of photoinduced quasiparticles in the heavy-fermion superconductor PuCoGa5. The deduced electron-phonon coupling constant is incompatible with the measured superconducting transition temperature Tc=18.5 K, which speaks against phonon-mediated superconductivity. Upon lowering the temperature, we observe an order-of-magnitude increase of the quasiparticle relaxation time in agreement with the phonon bottleneck scenario--evidence for a hybridization gap in the electronic density of states. The modification of photoinduced reflectance in the superconducting state is consistent with the heavy character of the quasiparticles that participate in Cooper pairing.
我们研究了重费米子超导体 PuCoGa5 中光诱导准粒子的弛豫。得出的电子-声子耦合常数与测量得到的超导转变温度 Tc=18.5 K 不兼容，这表明声子介导的超导性是不可能的。随着温度的降低，我们观察到准粒子弛豫时间的数量级增加，这与声子瓶颈情景一致——这是电子态密度中杂化间隙的证据。超导状态下光诱导反射率的变化与参与库珀配对的准粒子的重性质一致。
