AMPLITUDE COLLECTIVE MODES IN SUPERCONDUCTORS AND THEIR COUPLING TO CHARGE-DENSITY WAVES
AMPLITUDE COLLECTIVE MODES IN SUPERCONDUCTORS AND THEIR COUPLING TO CHARGE-DENSITY WAVES
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DOI：
10.1103/physrevb.26.4883
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发表时间：
1982-01-01
影响因子：
3.7
通讯作者：
VARMA, CM
中科院分区：
文献类型：
--
作者：
LITTLEWOOD, PB;VARMA, CM
在低温下，超导带隙振幅的长波长扰动以有限频率的无阻尼集体模传播。计算了该模式的色散和阻尼。超导体的相位或Bogoliubov模式受到库仑相互作用的强烈影响，并且与等离子体激元无法区分。相比之下，振幅模式示出不扰动的电荷密度，从而保持不受库仑相互作用。在某些条件下，长波长声子耦合到该模式。推导了这种耦合，并定量解释了通过电荷密度波化合物Nb Se 2的拉曼散射实验观察到的振幅模式。
At low temperature the long-wavelength perturbations of the amplitude of the superconducting gap propagate as an undamped collective mode with a finite frequency. The dispersion and damping of this mode are calculated. The phase or the Bogoliubov modes of a superconductor are strongly affected by Coulomb interactions and rendered indistinguishable from plasmons. By contrast, the amplitude modes are shown not to perturb the charge density thus remaining unaffected by the Coulomb interactions. Under certain conditions long-wavelength phonons couple to this mode. This coupling is derived and the observation of the amplitude mode through Raman scattering experiments in the charge-density-wave compound Nb Se 2 are quantitatively explained.