Yamakawa Youichi, Kontani Hiroshi
Department of Physics, Nagoya University, Furo-cho, Nagoya 464-8602, Japan.
Phys Rev Lett. 2015 Jun 26;114(25):257001. doi: 10.1103/PhysRevLett.114.257001. Epub 2015 Jun 23.
We present a microscopic derivation of the nematic charge-density wave (CDW) formation in cuprate superconductors based on the three-orbital d-p Hubbard model by introducing the vertex correction (VC) into the charge susceptibility. The CDW instability at q=(Δ(FS),0), (0,Δ(FS)) appears when the spin fluctuations are strong, due to the strong charge-spin interference represented by the VC. Here, Δ(FS) is the wave number between the neighboring hot spots. The obtained spin-fluctuation-driven CDW is expressed as the "intra-unit-cell orbital order" accompanied by the charge transfer between the neighboring atomic orbitals, which is actually observed by the scanning tunneling microscope measurements. We predict that the cuprate CDW and the nematic orbital order in Fe-based superconductors are closely related spin-fluctuation-driven phenomena.
我们基于三轨道d-p哈伯德模型,通过在电荷磁化率中引入顶点修正(VC),给出了铜酸盐超导体中向列型电荷密度波(CDW)形成的微观推导。当自旋涨落很强时,由于VC所代表的强电荷-自旋干涉,在q = (Δ(FS),0)、(0,Δ(FS))处会出现CDW不稳定性。这里,Δ(FS)是相邻热点之间的波数。所得到的自旋涨落驱动的CDW表现为“晶胞内轨道序”,伴随着相邻原子轨道之间的电荷转移,这实际上已被扫描隧道显微镜测量所观测到。我们预测,铜酸盐CDW和铁基超导体中的向列型轨道序是密切相关的自旋涨落驱动现象。