dc.contributor.author Bergeron, Dominic dc.contributor.author Chowdhury, Debanjan dc.contributor.author Punk, Matthias dc.contributor.author Sachdev, Subir dc.contributor.author Tremblay, A.-M. S. dc.date.accessioned 2013-07-26T14:37:18Z dc.date.issued 2012 dc.identifier.citation Bergeron, Dominic, Debanjan Chowdhury, Matthias Punk, Subir Sachdev, and A. -M. S. Tremblay. 2012. Breakdown of Fermi liquid behavior at the (π,π)=2k$_F$ spin-density wave quantum-critical point: the case of electron-doped cuprates. Physical Review B 86(15): 155123. en_US dc.identifier.issn 1098-0121 en_US dc.identifier.uri http://nrs.harvard.edu/urn-3:HUL.InstRepos:10886840 dc.description.abstract Many correlated materials display a quantum-critical point between a paramagnetic and a spin-density wave (SDW) state. The SDW wave vector connects points, so-called hot spots, on opposite sides of the Fermi surface. The Fermi velocities at these pairs of points are in general not parallel. Here, we consider the case where pairs of hot spots coalesce, and the wave vector (π,π) of the SDW connects hot spots with parallel Fermi velocities. Using the specific example of electron-doped cuprates, we first show that Kanamori screening and generic features of the Lindhard function make this case experimentally relevant. The temperature dependence of the correlation length, the spin susceptibility, and the self-energy at the hot spots are found using the two-particle self-consistent theory and specific numerical examples worked out for band and interaction parameters characteristic of the electron-doped cuprates. While the curvature of the Fermi surface at the hot spots leads to deviations from perfect nesting, the pseudonesting conditions lead to drastic modifications of the temperature dependence of these physical observables: Neglecting logarithmic corrections, the correlation length ξ scales like 1/T, namely, z=1 instead of the naive z=2, the (π,π) static spin susceptibility χ like 1/$\sqrt{T}$, and the imaginary part of the self-energy at the hot spots like T$^{3/2}$. The correction T$_1$$^{−1}$∼T$^{3/2}$ to the Korringa NMR relaxation rate is subdominant. We also consider this problem at zero temperature, or for frequencies larger than temperature, using a field-theoretical model of gapless collective bosonic modes (SDW fluctuations) interacting with fermions. The imaginary part of the retarded fermionic self-energy close to the hot spots scales as −ω$^{3/2}$lnω. This is less singular than earlier predictions of the form −ωlnω. The difference arises from the effects of umklapp terms that were not included in previous studies. en_US dc.description.sponsorship Physics en_US dc.language.iso en_US en_US dc.publisher American Physical Society en_US dc.relation.isversionof doi:10.1103/PhysRevB.86.155123 en_US dash.license OAP dc.title Breakdown of Fermi Liquid Behavior at the (π,π)=2k$_F$ Spin-Density Wave Quantum-Critical Point: the Case of Electron-Doped Cuprates en_US dc.type Journal Article en_US dc.description.version Accepted Manuscript en_US dc.relation.journal Physical Review B en_US dash.depositing.author Sachdev, Subir dc.date.available 2013-07-26T14:37:18Z dc.identifier.doi 10.1103/PhysRevB.86.155123 * dash.contributor.affiliated Chowdhury, Debanjan dash.contributor.affiliated Punk, Matthias dash.contributor.affiliated Sachdev, Subir
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