Quantum Higgs Echo in Superconductors: A Novel Form of Quantum Memory

This paper presents a comprehensive theoretical investigation of quantum information storage via the Higgs amplitude mode in superconductors. We propose a novel quantum memory mechanism based on coherent excitation and echo retrieval of the Higgs mode, exploiting the collective nature of the superconducting condensate. Through rigorous theoretical analysis combining time-dependent Ginzburg-Landau theory with quantum master equations, we demonstrate that Higgs mode excitations can store quantum information with coherence times exceeding 100 ns. We derive analytical expressions for storage fidelity as a function of temperature, gap anisotropy, and disorder, achieving theoretical fidelities above 95% for storage times up to 100 ns in clean s-wave superconductors below. Numerical simulations validate our theoretical predictions and reveal optimal parameter regimes for NbN thin films. Our findings establish fundamental bounds on Higgs-based quantum memory and propose experimental protocols compatible with current THz spectroscopy capabilities. This work opens new directions for exploiting collective modes in quantum technologies.