Extinction of quasiparticle interference in underdoped cuprates with coexisting order

Abstract

Recent scanning tunnelling spectroscopy measurements [Y. Koksaka et al., Nature 454, 1072] have shown that dispersing quasiparticle interference peaks in Fourier transformed conductance maps disappear as the bias voltage exceeds a certain threshold corresponding to the coincidence of the contour of constant quasiparticle energy with the antiferromagnetic zone boundary. Here we argue that this is caused by quasistatic short-range coexisting order present in the d-wave superconducting phase, and that the most likely origin of this order is disorder-induced incommensurate antiferromagnetism. We show explicitly how the peaks are extinguished in the related situation with coexisting long-range antiferromagnetic order, and discuss the connection with the realistic disordered case. Since it is the localized quasiparticle interference peaks rather than the underlying antinodal states themselves which are destroyed at a critical bias, our proposal resolves a conflict between scanning tunneling spectroscopy and photoemission regarding the nature of these states.

Subgap structures and pseudogap in cuprate superconductors: Role of density waves

“…Notably, in Ref. 42, it was shown, along with results comparable to ours, but for spin DW, that adding disorder to long-ranged commensurate DW systems simply spreads otherwise sharp features found in the spectra, without changing the qualitative conclusions. This approach finds additional justification from work showing how strong correlations generically protect dwave superconductivity against disorder 45,46 .…”

“…In the past, similar simplifications were used to successfully obtain DW-induced quantum oscillation frequencies in YBCO 36 , and also to address the closely related question of how spin density waves can reconcile the photoemission and tunneling observations in cuprates 42 . The interest of such simplifications comes from the wide range of parameters that can be tested.…”

Quasiparticle interference and the interplay between superconductivity and density wave order in the cuprates

“…Calculations of QPI from single site and multiple impurities 29,32,[42][43][44] reproduce the locations of experimentally measured wavevectors, but the features in the QPI pattern are "streak-like" rather than "point-like" as in experiment. Zhu et.al 45 studied QPI from multiple impurities, and highlighted the need for more realistic impurity models.…”

“…31 Additionally, the presence of a competing spin DW order coexisting with superconductivity can explain the disappearance of QPI beyond the AFZB. 32 In addition to dispersing octet q-vectors from superconducting QPI, static quasi-periodic "checkerboard" modulations have been observed in both the superconducting and pseudogap phases. 13,15,[17][18][19][21][22][23][24]26,27 Although the origin of these modulations remains unknown, there has been much discussion about their relation to a possible DW order in the pseudogap phase; scenarios that have been proposed include orbital current induced d-density waves, 33 one dimensional stripes, 34 nematic order, 35 short range charge order connected to nested parts of the Fermi surface in antinodal regions, 23,[36][37][38] and disorder-induced charge orders.…”

Universal disorder in Bi2Sr2CaCu2OAlldredge1, Fujita2, Eisaki3 et al. 2013Phys. Rev. B

“…The nature of the state between the superconducting and the pseudogap state, with a separate excitation that is linked to the PAF-zone boundary and a locally determined Fermi surface, is still a mystery. This state could be driven by AF flucutations 58,59 or scattering between the ends of the band structure 60 , however the local change observed here and elsewhere 17 of the q 1 * modulations effective band structure is unexplained. The determination that the q 1 * modulation is linked locally to the kink, as well as the determination of its energy span with doping will aid in the determination of origin and identification of this state.…”