Optimizing the Critical Temperature and Superfluid Density of a Metal-Superconductor Bilayer

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Zhang, Yutan, Dee, Philip M., Cohen-Stead, Benjamin, Maier, Thomas A., Johnston, Steven, Scalettar, Richard
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866918124675137536
author Zhang, Yutan
Dee, Philip M.
Cohen-Stead, Benjamin
Maier, Thomas A.
Johnston, Steven
Scalettar, Richard
author_facet Zhang, Yutan
Dee, Philip M.
Cohen-Stead, Benjamin
Maier, Thomas A.
Johnston, Steven
Scalettar, Richard
contents A promising path to realizing higher superconducting transition temperatures $T_c$ is the strategic engineering of artificial heterostructures. For example, quantum materials could, in principle, be coupled with other materials to produce a more robust superconducting state. In this work, we add numerical support to the hypothesis that a strongly interacting superconductor weakened by phase fluctuations can boost its $T_c$ by hybridizing the system with a metal. Using determinant quantum Monte Carlo (DQMC), we simulate a two-dimensional bilayer composed of an attractive Hubbard model and a metallic layer in two regimes of the interaction strength $-|U|$. In the strongly interacting regime, we find that increasing the interlayer hybridization $t_\perp$ results in a nonmonotonic enhancement of $T_c$, with an optimal value comparable to the maximum $T_c$ observed in the single-layer attractive Hubbard model, confirming trends inferred from other approaches. In the intermediate coupling regime, when $-|U|$ is close to the value associated with the maximum $T_c$ of the single-layer model, increasing $t_\perp$ tends to decrease $T_c$, implying that the correlated layer was already optimally tuned. Importantly, we demonstrate that the mechanism behind these trends is related to enhancement in the superfluid stiffness, as was initially proposed by Kivelson [Physica B: Condensed Matter 318, 61 (2002)].
format Preprint
id arxiv_https___arxiv_org_abs_2501_15428
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Optimizing the Critical Temperature and Superfluid Density of a Metal-Superconductor Bilayer
Zhang, Yutan
Dee, Philip M.
Cohen-Stead, Benjamin
Maier, Thomas A.
Johnston, Steven
Scalettar, Richard
Superconductivity
Strongly Correlated Electrons
A promising path to realizing higher superconducting transition temperatures $T_c$ is the strategic engineering of artificial heterostructures. For example, quantum materials could, in principle, be coupled with other materials to produce a more robust superconducting state. In this work, we add numerical support to the hypothesis that a strongly interacting superconductor weakened by phase fluctuations can boost its $T_c$ by hybridizing the system with a metal. Using determinant quantum Monte Carlo (DQMC), we simulate a two-dimensional bilayer composed of an attractive Hubbard model and a metallic layer in two regimes of the interaction strength $-|U|$. In the strongly interacting regime, we find that increasing the interlayer hybridization $t_\perp$ results in a nonmonotonic enhancement of $T_c$, with an optimal value comparable to the maximum $T_c$ observed in the single-layer attractive Hubbard model, confirming trends inferred from other approaches. In the intermediate coupling regime, when $-|U|$ is close to the value associated with the maximum $T_c$ of the single-layer model, increasing $t_\perp$ tends to decrease $T_c$, implying that the correlated layer was already optimally tuned. Importantly, we demonstrate that the mechanism behind these trends is related to enhancement in the superfluid stiffness, as was initially proposed by Kivelson [Physica B: Condensed Matter 318, 61 (2002)].
title Optimizing the Critical Temperature and Superfluid Density of a Metal-Superconductor Bilayer
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2501.15428