97 citations · 661 across the 25 of their papers we have counts for
25 papers
Revisiting superconductivity in the extended one-band Hubbard model: pairing via spin and charge fluctuations
Mercè Roig, Astrid T. Rømer, P. J. Hirschfeld +1
The leading superconducting instabilities of the two-dimensional extended repulsive one-band Hubbard model within spin-fluctuation pairing theory depend sensitively on electron den…
Heat capacity double transitions in time-reversal symmetry broken superconductors
Henrik S. Røising, Glenn Wagner, Mercè Roig +2
Standard superconductors display a ubiquitous discontinuous jump in the electronic specific heat at the critical superconducting transition temperature. In a growing class of uncon…
Superconductivity from repulsive interactions on the kagome lattice
Astrid T. Rømer, Shinibali Bhattacharyya, Roser Valentí +2
The discovery of superconductivity in layered vanadium-based kagome metals VSb (: K, Rb, Cs) has added a new family of materials to the growing class of possible unco…
Leading superconducting instabilities in three-dimensional models for Sr2RuO4
Astrid T. Rømer, T. A. Maier, Andreas Kreisel +2
The superconductor Sr2RuO4 has been the subject of enormous interest over more than two decades, but until now the form of its order parameter has not been determined. Since ground…
Superconductivity in multiorbital systems with repulsive interactions: Hund's pairing vs. spin-fluctuation pairing
Mercè Roig, Astrid T. Rømer, Andreas Kreisel +2
Hund's pairing refers to Cooper pairing generated by onsite interactions that become attractive due to large Hund's exchange . This is possible in multiorbital systems even when…
Evolution of magnetic stripes under uniaxial stress in LaBaCuO studied by neutron scattering
Machteld E. Kamminga, Kristine M. L. Krighaar, Astrid T. Rømer +6
Here we present the effect of uniaxial stress on the magnetic stripes in the cuprate system LaBaCuO with , previously found to have a stress-induced en…
Superconducting Instabilities in Strongly-Correlated Infinite-Layer Nickelates
Andreas Kreisel, Brian M. Andersen, Astrid T. Rømer +2
The discovery of superconductivity in infinite-layer nickelates has added a new family of materials to the fascinating growing class of unconventional superconductors. By incorpora…
Superconducting gap symmetry from Bogoliubov quasiparticle interference analysis on {Sr}{RuO}
Shinibali Bhattacharyya, Andreas Kreisel, X. Kong +4
The nature of the superconducting order parameter in {Sr}{RuO} has generated intense interest in recent years. Since the superconducting gap is very small, high resolution…
Superconducting state of SrRuO in the presence of longer-range Coulomb interactions
Astrid T. Rømer, P. J. Hirschfeld, Brian M. Andersen
The symmetry of the superconducting condensate in SrRuO remains controversial after nuclear magnetic resonance (NMR) experiments recently overturned the dominant chiral …
Orbital-dependent self-energy effects and consequences for the superconducting gap structure in multi-orbital correlated electron systems
Kristofer Björnson, Andreas Kreisel, Astrid T. Rømer +1
We perform a theoretical study of the effects of electronic correlations on the superconducting gap structure of multi-band superconductors. In particular, by comparing standard RP…
Nature of the magnetic stripes in fully oxygenated LaCuO
Ana-Elena Tutueanu, Henrik Jacobsen, Pia Jensen Ray +12
We present triple-axis neutron scattering studies of static and dynamic magnetic stripes in an optimally oxygen-doped cuprate superconductor, LaCuO, which exhibits a…
Theory of Strain-Induced Magnetic Order and Splitting of and in SrRuO
Astrid T. Rømer, Andreas Kreisel, Marvin A. Müller +3
The internal structure of the superconducting state in SrRuO remains elusive at present, and exhibits evidence for time-reversal symmetry breaking. Recent muon spin relaxat…
Fluctuation-driven superconductivity in SrRuO from weak repulsive interactions
Astrid T. Rømer, Brian M. Andersen
We provide results for the leading superconducting instabilities for a model pertaining to SrRuO obtained within spin-fluctuation mediated superconductivity in the very wea…
Pairing in the Two-Dimensional Hubbard Model from Weak to Strong Coupling
Astrid T. Rømer, Thomas A. Maier, Andreas Kreisel +3
The Hubbard model is the simplest model that is believed to exhibit superconductivity arising from purely repulsive interactions, and has been extensively applied to explore a vari…
Anomalous Dispersion of LO Phonons in Oxygen-Doped LaSrCuO
Tim Tejsner, Andrea Piovano, Ana Ţuţueanu +5
Inelastic neutron scattering has been used to study the in-plane Cu-O bond-stretching mode in oxygen doped LaSrCuO () and LaCuO$…
Knight Shift and Leading Superconducting Instability From Spin Fluctuations in Sr2RuO4
A. T. Rømer, D. D. Scherer, I. M. Eremin +2
Recent nuclear magnetic resonance studies [A. Pustogow {\it et al.}, arXiv:1904.00047] have challenged the prevalent chiral triplet pairing scenario proposed for SrRuO. To…
Exact diagonalization study of the Hubbard-parametrized four-spin ring exchange model on a square lattice
C. B. Larsen, A. T. Rømer, S. Janas +5
We have used exact numerical diagonalization to study the excitation spectrum and the dynamic spin correlations in the next-next-nearest neighbor Heisenberg antiferromagnet…
Raising the critical temperature by disorder in unconventional superconductors mediated by spin fluctuations
Astrid T. Roemer, P. J. Hirschfeld, Brian M. Andersen
We propose a mechanism whereby disorder can enhance the transition temperature Tc of an unconventional superconductor with pairing driven by exchange of spin fluctuations. The theo…
Distinct nature of static and dynamic magnetic stripes in cuprate superconductors
H. Jacobsen, S. L. Holm, M. -E. Lacatusu +9
We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, LaCuO. We find that the dynamic…
Superconducting phase diagram of the paramagnetic one-band Hubbard model
Andreas Kreisel, Astrid T. Roemer, Peter J. Hirschfeld +1
We study spin-fluctuation-mediated superconductivity in the one-band Hubbard model. Higher order effective interactions in give rise to a superconducting instability which is v…
Pairing symmetry of the one-band Hubbard model in the paramagnetic weak-coupling limit: a numerical RPA study
A. T. Romer, A. Kreisel, I. Eremin +4
We study the spin-fluctuation-mediated superconducting pairing gap in a weak-coupling approach to the Hubbard model for a two dimensional square lattice in the paramagnetic state.…
Field-induced inter-planar correlations in the high-temperature superconductor La1.88Sr0.12CuO4
A. T. Roemer, P. Jensen, H. Jacobsen +14
We present neutron scattering studies of the inter-planar correlations in the high-temperature superconductor La1.88Sr0.12CuO4 (T_c=27 K). The correlations are studied both in a ma…
Doping asymmetry of superconductivity coexisting with antiferromagnetism in spin fluctuation theory
W. Rowe, I. Eremin, A. Rømer +2
We generalize the theory of Cooper pairing by spin excitations in the metallic antiferromagnetic state to include situations with electron and/or hole pockets. We show that Cooper…
Glassy low-energy spin fluctuations and anisotropy gap in La1.88Sr0.12CuO4
A. T. Rømer, J. Chang, N. B. Christensen +13
We present high-resolution triple-axis neutron scattering studies of the high-temperature superconductor La1.88Sr0.12CuO4 (Tc=27 K). The temperature dependence of the low-energy in…