# Particle–hole symmetry breaking in the pseudogap state of Bi2201

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Zahid Hussain, Jul 28, 2015 Available from:-
- "Our routine sets the in-gap points of Σ eff (ω) to zero and computes the transformation by Fast Fourier transform assuming electronhole symmetry. We have verified by simulations that a possible violation of electron-hole symmetry [16] should not significantly alter the findings here. We note that Eq. 1 is a conventional definition of Σ eff . "

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**ABSTRACT:**Ultrahigh resolution angle-resolved photoemission spectroscopy with low-energy photons is used to study the detailed momentum dependence of the well-known nodal "kink" dispersion anomaly of Bi2Sr2CaCu2O8+{\delta}. We find that the kink's location transitions smoothly from a maximum binding energy of about 65 meV at the node of the d-wave superconducting gap to 55 meV roughly one-third of the way to the antinode. Meanwhile, the self-energy spectrum corresponding to the kink dramatically sharpens and intensifies beyond a critical point in momentum space. We discuss the possible bosonic spectrum in energy and momentum space that can couple to the k-space dispersion of the electronic kinks. - [Show abstract] [Hide abstract]

**ABSTRACT:**The recent discovery of unusual magnetic modes in the CuO2 planes of high-temperature superconducting cuprates HgBa2CuO4+δ in the pseudogap phase, if confirmed, suggests the existence of a new phase of condensed matter. The present situation is controversial since recent measurements of the magnetic environment of barium atoms in YBa2Cu4O8 obtained negative results. The theoretical situation is also controversial since several theoretical studies of the same three-band Hubbard model gave conflicting results. However, the important experimental evidence of ubiquitous strong electron-lattice interaction remains to be understood and we investigate the question of whether orbital currents can exist in an electron-lattice model. We show in a simple physical picture that if a predominant mode of vibration of the oxygens is an unusual planar non-linear mode, orbital currents can be generated. Simple order of magnitude estimates of the magnetic fields generated are remarkably in agreement with an experimental measurement.Journal of Superconductivity and Novel Magnetism 12/2014; 25(4). DOI:10.1007/s10948-011-1369-0 · 0.93 Impact Factor -
##### Article: Modeling a striped pseudogap state

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**ABSTRACT:**We study the electronic structure within a system of phase-decoupled one-dimensional superconductors coexisting with stripe spin and charge density wave order. This system has a nodal Fermi surface (Fermi arc) in the form of a hole pocket and an antinodal pseudogap. The spectral function in the antinodes is approximately particle-hole symmetric contrary to the gapped regions just outside the pocket. We find that states at the Fermi energy are extended whereas states near the pseudogap energy have localization lengths as short as the inter-stripe spacing. We consider pairing which has either local d-wave or s-wave symmetry and find similar results in both cases, consistent with the pseudogap being an effect of local pair correlations. We suggest that this state is a stripe ordered caricature of the pseudogap phase in underdoped cuprates with coexisting spin-, charge-, and pair-density wave correlations. Lastly, we also model a superconducting state which 1) evolves smoothly from the pseudogap state, 2) has a signature subgap peak in the density of states, and 3) has the coherent pair density concentrated to the nodal region. Comment: 12 pages, 12 figures, extended discussion, added references; v3, added figure of antinodal spectra for normal/pseudo/sc statesPhysical review. B, Condensed matter 10/2009; 81(2). DOI:10.1103/PhysRevB.81.024501 · 3.66 Impact Factor