Magnetic field expulsion in optically driven YBa2Cu3O6.48

• 成果类型: Article
• 署名作者: Fava, S.; De Vecchi, G.; Jotzu, G.; Buzzi, M.; Gebert, T.; Liu, Y.; Keimer, B.; Cavalleri, A.
• 署名单位: Max Planck Society; Max Planck Society; University of Oxford
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4936
• DOI: 10.1038/s41586-024-07635-2
• 发表日期: 2024-08-01
• 页码: 75-+
• 关键词: light-induced superconductivity; ferroelectricity

摘要

Coherent optical driving in quantum solids is emerging as a research frontier, with many reports of interesting non-equilibrium quantum phases(1-4) and transient photo-induced functional phenomena such as ferroelectricity(5,6), magnetism(7-10) and superconductivity(11-14). In high-temperature cuprate superconductors, coherent driving of certain phonon modes has resulted in a transient state with superconducting-like optical properties, observed far above their transition temperature T-c and throughout the pseudogap phase(15-18). However, questions remain on the microscopic nature of this transient state and how to distinguish it from a non-superconducting state with enhanced carrier mobility. For example, it is not known whether cuprates driven in this fashion exhibit Meissner diamagnetism. Here we examine the time-dependent magnetic field surrounding an optically driven YBa2Cu3O6.48 crystal by measuring Faraday rotation in a magneto-optic material placed in the vicinity of the sample. For a constant applied magnetic field and under the same driving conditions that result in superconducting-like optical properties(15-18), a transient diamagnetic response was observed. This response is comparable in size with that expected in an equilibrium type II superconductor of similar shape and size with a volume susceptibility chi(v) of order -0.3. This value is incompatible with a photo-induced increase in mobility without superconductivity. Rather, it underscores the notion of a pseudogap phase in which incipient superconducting correlations are enhanced or synchronized by the drive.