High-throughput search for lossless metals

Hypothetical metals having optical absorption losses as low as those of the transparent insulators, if found, could revolutionize optoelectronics. We perform a high-throughput search for lossless metals among all known inorganic materials in the databases of over 100 000 entries. The 381 candidates are identified---having well-isolated partially filled bands---and are analyzed by defining the figures of merit and classifying their real-space conductive connectivity. The superconductor lithium titanate is shown to satisfy the lossless criteria but have a limited bandwidth for low loss. The existing experimental evidence of most candidates being insulating, instead of conducting, is due to the limitation of current density functional theory in predicting narrow-band metals that are unstable against magnetism, structural distortion, or electron-electron interactions. We propose future research directions including conductive oxides, intercalating layered materials, and compressing these false-metal candidates under high pressures into eventual lossless metals.