Correlation between phase stiffness and condensation energy across the non-Fermi to Fermi-liquid crossover in the Yukawa-Sachdev-Ye-Kitaev model on a lattice

Correlation between phase stiffness and condensation energy across the non-Fermi to Fermi-liquid crossover in the Yukawa-Sachdev-Ye-Kitaev model on a lattice

Blog Article

We construct and analyze a lattice generalization of the Yukawa-Sachdev-Ye-Kitaev model, where spinful fermions experience onsite, random, all-to-all interactions with an Einstein bosonic mode, and random intersite coherent hopping.We obtain the exact tennessee titans dog bandana self-consistent numerical solution of the model at mean-field level, and analytical approximations, for all values of fermion-boson coupling and hopping, under the spin-singlet ansatz and at particle-hole symmetry, both in the normal and superconducting states, thus tracing the entire phase diagram.In the normal state, the competition between hopping and coupling leads to crossovers between Fermi-liquid and non-Fermi-liquid states, as reflected by the fermionic and bosonic spectral functions and the normal-state entropy.We calculate the finite phase stiffness of the superconducting state through the equilibrium electromagnetic response.Furthermore, we study the critical temperature T_{c}, as well as the spectral functions, the quasiparticle weight, the gap, and the condensation energy in the superconducting state.

At weak coupling, we retrieve a disordered generalization of Bardeen-Cooper-Schrieffer theory.At strong coupling, asymptotically T_{c} saturates but the stiffness decreases, which suggests strong superconducting fluctuations.T_{c} is maximum in the single-dot limit, while the stiffness peaks exactly at the crossover between non-Fermi-liquid and Fermi-liquid phases.We discover that the quasiparticle weight, the stiffness, and the condensation energy, are all correlated as a function 1073spx of coupling, reminiscent of the correlations observed in high-temperature cuprate superconductors.