Inhomogeneous d-wave superconducting state of a doped Mott insulator

	Inhomogeneous d-wave superconducting state of a doped Mott insulator
	Wang, ZQ ; Engelbrecht, JR ; Wang, SC ; Ding, H ; Pan, SHH
刊名	PHYSICAL REVIEW B
	2002
卷号	65 期号:6
关键词	T-J-MODEL 2-DIMENSIONAL ELECTRON-GAS VALENCE BOND STATE DENSITY-OF-STATES FERMI-LIQUID BI2SR2CACU2O8+DELTA IMPURITY SCATTERING LOCALIZATION EXCITATIONS
ISSN号	1098-0121
通讯作者	Wang, ZQ (reprint author), Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA.
中文摘要	Recent atomic resolution scanning tunneling microscope (STM) measurements discovered remarkable electronic inhomogeneity, i.e., nanoscale spatial variations of the local density of states (LDOS) and the superconducting energy gap, in the high-T-c superconductor Bi2Sr2CaCu2O8 + x. Based on the experimental findings, we conjectured that the inhomogeneity arises from variations in local oxygen doping level and may be generic of doped Mott insulators. In this paper, we provide theoretical support for this picture, We study a doped Mott insulator within a generalized t-J model, where doping is accompanied by ionic Coulomb potentials centered in the BiO plane located a distance d(s) away from the CuO2 plane. We solve, at the mean-field level, a set of spatially unrestricted Bogoliubov-de Gennes equations self-consistently to obtain the distributions of the hole concentration, the valence bond, and the pairing order parameters for different nominal/average doping concentrations. We calculate the LDOS spectrum, the integrated LDOS, and the local superconducting gap as those measured by STM, make detailed comparisons to experiments, and find remarkable agreement with the experimental data. We emphasize the unconventional screening of the ionic potential in a doped Mott insulator and show that nonlinear screening dominates on nanometer scales, comparable to the short coherence length of the superconductor. which is the origin of the electronic inhomogeneity. It leads to strong inhomogeneous redistribution of the local hole density and promotes the notion of local doping concentration (LDC). We find that the inhomogeneity structure manifests itself at all energy scales in the STM tunneling differential conductance. and elucidate the similarity and the differences between the data obtained in the constant tunneling current mode and the same data normalized to reflect constant tip-to-sample distance. We also discuss the underdoped case where nonlinear screening of the ionic potential turns the spatial electronic structure into a percolative mixture of patches with smaller pairing gaps embedded in a background with larger gaps to single particle excitations.
收录类别	SCI
语种	英语
公开日期	2014-02-20
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/57958]
专题	物理研究所_所内人员在其他单位发表论文题录信息_所内人员在其他单位发表论文题录信息_期刊论文
推荐引用方式 GB/T 7714	Wang, ZQ,Engelbrecht, JR,Wang, SC,et al. Inhomogeneous d-wave superconducting state of a doped Mott insulator[J]. PHYSICAL REVIEW B,2002,65(6).
APA	Wang, ZQ,Engelbrecht, JR,Wang, SC,Ding, H,&Pan, SHH.(2002).Inhomogeneous d-wave superconducting state of a doped Mott insulator.PHYSICAL REVIEW B,65(6).
MLA	Wang, ZQ,et al."Inhomogeneous d-wave superconducting state of a doped Mott insulator".PHYSICAL REVIEW B 65.6(2002).