Superconductivity at an antiferromagnetic quantum critical point: the role of energy fluctuations

Abstract

Motivated by recent experiments reporting superconductivity only at very low temperature in a class of heavy fermion compounds, we study the impact of energy fluctuations with small momentum transfer on the pairing instability near an antiferromagnetic quantum critical point. While these fluctuations, formed by composite spin fluctuations, were proposed to explain the thermodynamic and transport properties near the quantum critical point of compounds such as YbRh${}_2$Si${}_2$ and CeCu${}_{6-x}$Au${}_x$ at $x\approx 0.1$, here they are found to strongly suppress $T_c$ of the $d$-wave pairing of the hot quasiparticles promoted by the spin fluctuations. Interestingly, if energy fluctuations are strong enough, they can induce triplet pairing involving the quasiparticles of the cold regions of the Fermi surface. Overall, the opposing effects of energy and spin fluctuations lead to a suppression of $T_c$.

arXiv comment7 pages, 4 figures

References in corpus (18)

• A Common Thread: the pairing interaction for the unconventional superconductors
• Gap symmetry and structure of Fe-based superconductors
• Quantum phase transitions of metals in two spatial dimensions: II. Spin density wave order
• Quantum phase transitions of metals in two spatial dimensions: I. Ising-nematic order
• Are non-Fermi-liquids stable to Cooper pairing?
• Sign-problem-free quantum Monte Carlo of the onset of antiferromagnetism in metals
• Emergence of superconductivity in the canonical heavy-electron metal YbRh2Si2
• Metallic quantum critical points with finite BCS couplings
• Superconductivity near a quantum-critical point: The special role of the first Matsubara frequency
• Quantum critical response at the onset of spin density wave order in two-dimensional metals
• Quasi-Local Strange Metal
• Quasiparticles beyond the Fermi liquid and heavy fermion criticality
• Strong coupling theory of heavy fermion criticality
• Observing the origin of superconductivity in quantum critical metals
• Superconductivity mediated by quantum critical antiferromagnetic fluctuations: The rise and fall of hot spots
• Strong coupling theory of heavy fermion criticality II
• Robustness of quantum critical pairing against disorder
• Vertex functions at finite momentum: Application to antiferromagnetic quantum criticality

Cited by in corpus (4)

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• Superconductivity in an extreme strange metal
• Superconductivity from energy fluctuations in dilute quantum critical polar metals
• Nearly-degenerate $p_x+i{p}_y$ and $d_{x^2-y^2}$ pairing symmetry in the heavy fermion superconductor YbRh${}_2$Si${}_2$