Enhancing $T_{\mathrm{c}}$ in a composite superconductor/metal bilayer system: a dynamical cluster approximation study

Abstract

It has been proposed that the superconducting transition temperature $T_{\mathrm{c}}$ of an unconventional superconductor with a large pairing scale but strong phase fluctuations can be enhanced by coupling it to a metal. However, the general efficacy of this approach across different parameter regimes remains an open question. Using the dynamical cluster approximation, we study this question in a system composed of an attractive Hubbard layer in the intermediate coupling regime, where the magnitude of the attractive Coulomb interaction $|U|$ is slightly larger than the bandwidth $W$, hybridized with a noninteracting metallic layer. We find that while the superconducting transition becomes more mean-field-like with increasing interlayer hopping, the superconducting transition temperature $T_{\mathrm{c}}$ exhibits a nonmonotonic dependence on the strength of the hybridization $t_{\perp }$. This behavior arises from a reduction of the effective pairing interaction in the correlated layer that out-competes the growth in the intrinsic pair-field susceptibility induced by the coupling to the metallic layer. We find that the largest $T_{\mathrm{c}}$ inferred here for the composite system is below the maximum value currently estimated for the isolated negative-$U$ Hubbard model.

arXiv comment7 pages, 4 figures

References in corpus (20)

• Continuous-time Monte Carlo methods for quantum impurity models
• Quantum Cluster Theories
• Vanishing of phase coherence in underdoped Bi_2Sr_2CaCu_2O_8+d
• Continuous-time auxiliary field Monte Carlo for quantum impurity models
• Field-enhanced diamagnetism in intense magnetic field in the pseudogap state of the cuprate $\rm Bi_2Sr_2CaCu_2O_{8+δ}
• High-spin to low-spin and orbital polarization transitions in multiorbital Mott systems
• Observation of pair condensation in the quasi-2D BEC-BCS crossover
• Fermions in 2D Optical Lattices: Temperature and Entropy Scales for Observing Antiferromagnetism and Superfluidity
• Dynamical mean-field theory for pairing and spin gap in the attractive Hubbard model
• The Structure of the Pairing Interaction in the 2D Hubbard Model
• Sub-matrix updates for the Continuous-Time Auxiliary Field algorithm
• Upper bounds on the superfluid stiffness and superconducting $T_c$: Applications to twisted-bilayer graphene and ultra-cold Fermi gases
• A route to high temperature superconductivity in composite systems
• Making High T${}_c$ Higher: A Theoretical Proposal
• DCA++: A software framework to solve correlated electron problems with modern quantum cluster methods
• Pairing correlations in the cuprates: a numerical study of the three-band Hubbard model
• Assessing the orbital selective Mott transition with variational wave functions
• Superfluid stiffness renormalization and critical temperature enhancement in a composite superconductor
• BCS-BEC Crossover in the Two-Dimensional Attractive Hubbard Model: Variational Cluster Approach
• The 2D attractive Hubbard model and the BCS-BEC crossover

Cited by in corpus (8)

• Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La${}_3$Ni${}_2$O${}_7$ under pressure
• Structural phase transition, $s_{\pm }$-wave pairing and magnetic stripe order in the bilayered nickelate superconductor La${}_3$Ni${}_2$O${}_7$ under pressure
• Trends in electronic structures and $s_{\pm }$-wave pairing for the rare-earth series in bilayer nickelate superconductor $R_3$Ni${}_2$O${}_7$
• Electronic structure, magnetic correlations, and superconducting pairing in the reduced Ruddlesden-Popper bilayer La${}_3$Ni${}_2$O${}_6$ under pressure: different role of $d_{3z^2-r^2}$ orbital compared with La${}_3$Ni${}_2$O${}_7$
• Optimizing the Critical Temperature and Superfluid Density of a Metal-Superconductor Bilayer
• Inversion symmetry breaking in bilayer multi-orbital Hubbard model with impurity approximation
• Enhanced superconductivity via layer differentiation in trilayer Hubbard model
• Strong enhancements to superconducting properties of 1D systems from metallic reservoirs