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Zhihan Qiao

Publications and source records attributed to Zhihan Qiao.

2 recordsLinked to original sources

Evidence for hidden order and its potential correlation with electron-hole asymmetry in iridate superlattices

Hidden order refers to an order that shapes the properties of quantum materials yet remains difficult to identify. Here we report signatures of a hidden order in doped iridate superlattices through an unexpected electron-hole asymmetry in the coupling between the insulating state and the antiferromagnetic (AFM) state. While carrier doping suppresses both states, they remain coupled in the electron-doped regime but decouple in the hole-doped regime. Structural analysis rules out octahedral rotation and tilting as the dominant origin of this asymmetry. Instead, magnetic characterization reveals evidences of a hidden order that only appears in the hole-doped regime. This hidden order emerges above TN and is closely associated with the AFM state, coinciding with an exceptionally strong magnetic scattering intensity and an anomalously robust magnetic coherence. Our results highlight that hole-doped iridates can be a promising platform for exploring hidden and unconventional ordering phenomena in spin-orbit-entangled quantum materials.

cond-mat.str-el↗

High-Pressure Tuning of Electrical Transport in Freestanding Oxide Films

Electrical transport in oxide thin films under high pressure remains largely unexplored due to the lack of a universal experimental strategy. Here we develop an approach that enables high-pressure transport measurements in freestanding oxide films by enhancing their mechanical robustness and integrating them with nanoscale high-pressure devices. As a demonstration, we investigate the resistivity of perovskite SrIrO3 films under hydrostatic pressure and uncover a pressure-driven semimetal-insulator transition near 2.5 GPa, followed by an insulator-metal transition around 9 GPa. In the monolayer limit, SrIrO3 remains insulating and robust against pressure up to 5.5 GPa. The contrasting pressure-dependent phase diagrams of three- and two-dimensional iridates reveal a strong interplay between dimensionality and hydrostatic pressure in correlated oxides. Our work establishes a general platform for exploring pressure-driven phenomena in low-dimensional quantum materials.

cond-mat.mtrl-sci↗