Multiscale Approach for Unconventional Superconductors

The remarkable electromagnetic characteristics inherent in unconventional superconductors have catalyzed the advancement of numerous technological innovations, spanning from energy-efficient power transmission and high-field magnets to sensitive detectors and quantum computing systems. Central to the functionality of these applications lies the superconducting characteristics, which govern pivotal phenomena including Cooper pair formation and macroscopic phase coherence, resulting in the attainment of zero electrical resistance, complete diamagnetism, and the Josephson tunneling effect. The complex phases and orders in these materials significantly alter their key electronic and magnetic properties, posing challenges in elucidating the underlying physics and further enhancing their functional capabilities. The multiscale approach, representing a useful strategy for understanding materials across diverse length scales using a variety of experimental tools, can reveal intricate details in real and reciprocal spaces, facilitating cross-validation. In this brief review, we introduce the principle of the multiscale approach along with examples demonstrating its efficacy in unraveling the electronic and magnetic properties of unconventional superconductors.