This paper presents a novel approach to phase-change memory (PCM) using a combination of phase-change material superlattices and nanocomposites (based on Ge4Sb6Te7). The authors achieve record-low power density (≈ 5 MW/cm²) and switching voltage (≈ 0.7 V) in PCM devices with the smallest dimensions to date (≈ 40 nm). These devices exhibit low resistance drift, good endurance (≈ 2 × 10^8 cycles), and fast switching (≈ 40 ns). The efficient switching is attributed to strong heat confinement within the superlattice materials and the nanoscale device dimensions. The microstructural properties of the Ge4Sb6Te7 nanocomposite and its high crystallization temperature ensure fast switching speed and stability. This work re-establishes PCM technology as a frontrunner for energy-efficient data storage and computing, particularly in the context of big data, high-performance computing, and data-centric artificial intelligence applications. The study also explores the use of different superlattices (Sb2Te3/GST467 and TiTe2/GST467) to further optimize the performance of PCM devices, demonstrating significant improvements in reset energy, switching speed, and endurance.This paper presents a novel approach to phase-change memory (PCM) using a combination of phase-change material superlattices and nanocomposites (based on Ge4Sb6Te7). The authors achieve record-low power density (≈ 5 MW/cm²) and switching voltage (≈ 0.7 V) in PCM devices with the smallest dimensions to date (≈ 40 nm). These devices exhibit low resistance drift, good endurance (≈ 2 × 10^8 cycles), and fast switching (≈ 40 ns). The efficient switching is attributed to strong heat confinement within the superlattice materials and the nanoscale device dimensions. The microstructural properties of the Ge4Sb6Te7 nanocomposite and its high crystallization temperature ensure fast switching speed and stability. This work re-establishes PCM technology as a frontrunner for energy-efficient data storage and computing, particularly in the context of big data, high-performance computing, and data-centric artificial intelligence applications. The study also explores the use of different superlattices (Sb2Te3/GST467 and TiTe2/GST467) to further optimize the performance of PCM devices, demonstrating significant improvements in reset energy, switching speed, and endurance.