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Abstract Advancements in materials synthesis have been key to unveil the quantum nature of electronic properties in solids by providing experimental reference points for a correct theoretical description. Here, we report hidden transport phenomena emerging in the ultraclean limit of the archetypical correlated electron system SrVO₃. The low temperature, low magnetic field transport was found to be dominated by anisotropic scattering, whereas, at high temperature, we find a yet undiscovered phase that exhibits clear deviations from the expected Landau Fermi liquid, which is reminiscent of strange-metal physics in materials on the verge of a Mott transition. Further, the high sample purity enabled accessing the high magnetic field transport regime at low temperature, which revealed an anomalously high Hall coefficient. Taken with the strong anisotropic scattering, this presents a more complex picture of SrVO₃that deviates from a simple Landau Fermi liquid. These hidden transport anomalies observed in the ultraclean limit prompt a theoretical reexamination of this canonical correlated electron system beyond the Landau Fermi liquid paradigm, and more generally serves as an experimental basis to refine theoretical methods to capture such nontrivial experimental consequences emerging in correlated electron systems. 

Among ABO3 perovskites, SrMoO3 possesses the lowest electrical resistivity in addition to having high optical transparency in the visible spectrum. This unusual combination of material properties allows it to be a potential replacement for indium tin oxide as a transparent electrode. Thus far, its thin film synthesis has been challenging and limited primarily to pulsed laser deposition and sputtering. Here, we report the growth of SrMoO3 thin films by suboxide molecular beam epitaxy. We demonstrate that optically transparent and conductive SrMoO3 films can be grown by supplying elemental strontium via a conventional effusion cell and thermally evaporating MoO3 pellets as a molybdenum source. The direct supply of a molecular oxygen flux to the MoO3 charge was utilized to prevent reduction to lower oxidation states of the charge to ensure congruent evaporation and, thus, a stable MoO3 molecular flux. The optimal growth conditions were found by varying the Sr to MoO3 flux ratio determined from quartz crystal microbalance measurements and monitoring the growth by reflection high-energy electron diffraction. SrMoO3 thin films with 21 nm thickness were confirmed to be optically transparent with transmission between 75 and 91% throughout the visible spectral range and electrically conducting with a room temperature resistivity of 5.0 × 10−5 Ω cm. This realization of this thin film growth method can be further expanded to the growth of other transition metal perovskites in which cations have extremely low vapor pressure and cannot be evaporated in elemental forms. 

Abstract The field of spintronics has seen a surge of interest in altermagnetism due to novel predictions and many possible applications. MnTe is a leading altermagnetic candidate that is of significant interest across spintronics due to its layered antiferromagnetic structure, high Neel temperature (T_N ≈ 310 K) and semiconducting properties. The results on molecular beam epitaxy (MBE) grown MnTe/InP(111) films are presented. Here, it is found that the electronic and magnetic properties are driven by the natural stoichiometry of MnTe. Electronic transport and in situ angle‐resolved photoemission spectroscopy show the films are natively metallic with the Fermi level in the valence band and the band structure is in good agreement with first‐principles calculations for altermagnetic spin‐splitting. Neutron diffraction confirms that the film is antiferromagnetic with planar anisotropy and polarized neutron reflectometry indicates weak ferromagnetism, which is linked to a slight Mn‐richness that is intrinsic to the MBE‐grown samples. When combined with the anomalous Hall effect, this work shows that the electronic response is strongly affected by the ferromagnetic moment. Altogether, this highlights potential mechanisms for controlling altermagnetic ordering for diverse spintronic applications.