Speaker
Description
We investigate the role of quantum geometry in the Meissner response of odd-frequency superconducting pairs in multiband systems. Odd-frequency pairing is commonly associated with a paramagnetic Meissner response, raising questions about the stability of the superconducting phase, particularly in multiband systems where such pairing is ubiquitous. Using analytical calculations in a general two-band model, we show that the quantum geometric contribution from odd-frequency pairs is always diamagnetic for interband processes, while intraband processes remain paramagnetic. Since odd-frequency pairing is generated by interband pairing, an overall diamagnetic response is often expected. We support these results with numerical calculations for both flat and dispersive band models. In flat-band systems, where geometric effects dominate, the diamagnetic odd-frequency contribution can exceed the even-frequency response. These findings demonstrate that quantum geometry stabilizes odd-frequency superconductivity and identify flat-band materials as promising candidates for realizing a diamagnetic Meissner effect from odd-frequency pairs.