Proposed parametric cooling of bilayer cuprate superconductors by terahertz excitation

TL;DR

This paper proposes a method to cool bilayer cuprate superconductors using terahertz excitation to modulate vibrational modes, potentially stabilizing superconductivity above the critical temperature.

Contribution

It introduces a parametric cooling scheme based on selective vibrational mode driving to suppress phase fluctuations in bilayer cuprates.

Findings

Modulation at the difference frequency suppresses interbilayer phase fluctuations.

The scheme could stabilize non-equilibrium superconductivity above T_c.

Potential for controlling superconducting states via terahertz excitation.

Abstract

We propose and analyze a scheme for parametrically cooling bilayer cuprates based on the selective driving of a $c$-axis vibrational mode. The scheme exploits the vibration as a transducer making the Josephson plasma frequencies time-dependent. We show how modulation at the difference frequency between the intra- and interbilayer plasmon substantially suppresses interbilayer phase fluctuations, responsible for switching $c$-axis transport from a superconducting to resistive state. Our calculations indicate that this may provide a viable mechanism for stabilizing non-equilibrium superconductivity even above $T_c$, provided a finite pair density survives between the bilayers out of equilibrium.