Hybridization-Controlled Pseudogap State in the Quantum Critical Superconductor CeCoIn5

Abstract

The origin of the partial suppression of the electronic density states in the enigmatic pseudogap behavior, which is at the core of understanding high-$T_c$ superconductivity, has been hotly contested as either a hallmark of preformed Cooper pairs or an incipient order of competing interactions nearby. Here, we report the quasi-particle scattering spectroscopy of the quantum critical superconductor CeCoIn${}_5$, where a pseudogap with energy ${\Delta }_g$ was manifested as a dip in the differential conductance ($dI/dV$) below the characteristic temperature of $T_g$. When subjected to external pressure, $T_g$ and ${\Delta }_g$ gradually increase, following the trend of increase in quantum entangled hybridization between Ce 4$f$ moment and conduction electrons. On the other hand, the superconducting (SC) energy gap and its phase transition temperature shows a maximum, revealing a dome shape under pressure. The disparate dependence on pressure between the two quantum states shows that the pseudogap is less likely involved in the formation of SC Cooper pairs, but rather is controlled by Kondo hybridization, indicating that a novel type of pseudogap is realized in CeCoIn${}_5$.

arXiv comment4 figures

References in corpus (33)

• The pseudogap in high-temperature superconductors: an experimental survey
• Scanning tunneling spectroscopy of high-temperature superconductors
• Heavy-fermion superconductivity in CeCoIn5 at 2.3K
• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Change of carrier density at the pseudogap critical point of a cuprate superconductor
• Superconductivity and Quantum Criticality in CeCoIn_5
• Pseudogap state from quantum criticality
• Imaging Cooper Pairing of Heavy Fermions in CeCoIn5
• Visualizing Nodal Heavy Fermion Superconductivity in CeCoIn5
• Direct observation of how the heavy fermion state develops in CeCoIn5
• Andreev Reflection in Heavy-Fermion Superconductors and Order Parameter Symmetry in CeCoIn_5
• Electron Cotunneling into a Kondo Lattice
• Universal Behavior in Heavy Electron Materials
• Hidden magnetism at the pseudogap critical point of a high temperature superconductor
• Pseudogap phase of cuprate superconductors confined by Fermi surface topology
• Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictides
• Evolution of the Kondo lattice electronic structure above the transport coherence temperature
• Pseudogaps in strongly interacting Fermi gases
• Diagonal Nematicity in the Pseudogap Phase of HgBa${}_2$CuO${}_{4+\delta }$
• Response of the Heavy-Fermion Superconductor CeCoIn${}_5$ to Pressure: Roles of Dimensionality and Proximity to a Quantum-Critical Point
• Evolution of Pairing Orders between Pseudogap and Superconducting Phases of Cuprate Superconductors
• The Fano effect in the point contact spectroscopy of heavy electron materials
• Pseudogap and singlet formation in cuprate and organic superconductors
• Structural investigations of CeIrIn${}_5$ and CeCoIn${}_5$ on macroscopic and atomic length scales
• Nature of the spin resonance mode in CeCoIn${}_5$
• Spin Fluctuations and the Pseudogap in Organic Superconductors
• Two-channel point-contact tunneling theory of superconductors
• Visualizing Heavy Fermion Confinement and Pauli-Limited Superconductivity in Layered CeCoIn5
• Spectroscopic Evidence for the Direct Involvement of Local Moments in the Pairing Process of the Heavy-Fermion Superconductor CeCoIn${}_5$
• Experimental verification of contact-size estimates in point-contact spectroscopy on superconductor/ferromagnet heterocontacts
• Differential Conductance and Defect States in the Heavy Fermion Superconductor CeCoIn${}_5$
• The Lorenz number in CeCoIn${}_5$ inferred from the thermal and charge Hall currents
• Origin of gap-like behaviors in URu${}_2$Si${}_2$: Combined study via quasiparticle scattering spectroscopy and resistivity measurements