Imaging the atomic-scale conflct between d-symmetry Cooper pairs and d-form factor density waves in underdoped cuprates

Mohammad H. Hamidian
Cornell University


A central issue of cuprate superconductivity research is to understand the nature of the pseudgogap phase and its relationship to the d-wave superconductivity. Using our recently developed technique of sub-lattice phase-resolved electronic structure visualization [1] within each CuO2 unit-cell, we discovered that the ground state of the cuprate pseudogap is a d-symmetry form factor density wave [2]. Although long predicted, such an unconventional density-wave state has not previously been observed in any condensed matter system. Next, our simultaneous visualizations of both real-space and momentum-space electronic structure across the cuprate phase diagram revealed that the famous (but mysterious) transition of momentum-space topology from “Fermi arc” to conventional Fermi surface occurs simultaneously with the disappearance of the d-form factor density wave [3]. Taken together these results provide an atomic scale understanding of the antagonism between the d-symmetry density waves and d-symmetry Cooper pairing in underdoped cuprates.


[1] Nature, 466, 347 (2011)
[2] PNAS, 111, E3-26 (2014)
[3] Science, 344, 612 (2014)