Holographic maps of quasiparticle interference

Abstract

The analysis of Fourier-transformed scanning-tunneling-microscopy (STM) images with subatomic resolution is a common tool for studying properties of quasiparticle excitations in strongly correlated materials. While Fourier amplitudes are generally complex valued, earlier analysis mostly considered only their absolute values. Their complex phases were deemed random, and thus irrelevant, due to the unknown positions of impurities in the sample. Here we show how to factor out these random phases by analysing overlaps between Fourier amplitudes that differ by reciprocal lattice vectors. The resulting holographic maps provide important and previouslyunknown information about the electronic structures of materials. When applied to superconducting cuprates, our method solves a long-standing puzzle of the dichotomy between equivalent wavevectors. We show that d-wave Wannier functions of the conduction band provide a natural explanation for experimental results that were interpreted as evidence for competing unconventional charge modulations. Our work opens a new pathway to identify the nature of electronic states in STM measurements.

Visualizing weakly bound surface Fermi arcs and their correspondence to bulk Weyl fermions

“…Strongly correlated electronic systems may also be probed in a similar fashion. For instance, QPI patterns in high-temperature superconductors ( 34 , 35 ), in which charge order has been recently reported, also exhibit replications. It would be enticing to apply our method of analysis to characterize the structure of the Bloch wave functions in such systems and to possibly unveil hidden spectroscopic features.…”

Friedel oscillations as a probe of fermionic quasiparticles

“…7 -see also Ref. [35] for an in-depth analysis of the phase correlations observed by Fujita et al 10 ). Finally, it naturally accounts for the non-trivial c-axis correlations observed in X-ray experiments (Fig.…”

“…As explained in Ref. [35], this shape affects the phase and intensity of the Fourier-transformed STM signal at large wavevector (beyond the central Brillouin zone), leading to subtle correlations that were interpreted as evidence of a competing order with d-form factor [10][11][12][13] . In this paper we focus on the central Brillouin zone, where the precise shape of the Wannier function is not very important.…”

The study of electronic nematicity in an overdoped (Bi, Pb)2Sr2CuO6+δ superconductor using scanning tunneling spectroscopy

“…On the other hand, the nematic order also coexists with other electronic orders, e.g., the charge order (smectic order) which is interpreted by a Landau-Ginzberg theory 9 . The charge order is recently identified as a d -form factor order with a sophisticated phase sensitive analysis 22–24 . The PG state and related charge order are believed to originate from strong-correlated doped Mott insulator 25, 26 , whereas the large FS is often related with a Fermi liquid behavior 2 .…”