Light-Matter Interaction in Ultrastable Tunneling Nanogaps.

Light emission and detection through tunnel junctions have emerged as a promising platform for studying nanoscale light-matter interactions, including electroluminescence and photoassisted transport. However, controlling these interactions in the tunneling regime has been challenging due to complex underlying mechanisms that remain poorly understood. A major obstacle is the difficulty in forming stable junctions that can function reliably over extended periods.

Identifying the Limits of Strain Engineering in NaNbO Ultrathin Films.

Epitaxial NaNbO ultrathin films are grown on single-crystal substrates with a wide range of compressive (-6.24%) and tensile (+7.13%) strain.

Interfacial Polarons Driven by Charge Transfer in WSe/Cuprate Superconductor Systems.

Understanding the electronic properties of doped copper-oxygen planes remains a significant challenge in condensed matter physics and is crucial to unraveling the mechanisms behind high-temperature superconductivity in cuprates. Recently, the observation of charge transfer and interfacial polarons in a superconducting interface has aroused extensive research interest. However, experimental data to investigate charge transfer on the CuO plane and the presence of polarons are still missing.

Bulk superconductivity near 40 K in hole-doped SmNiO at ambient pressure.

The discovery of superconductivity in the Ba-La-Cu-O system (the cuprate) in the 30 K range marked a significant breakthrough, which inspired extensive exploration of oxide-based, layered superconductors to identify electron pairing with higher critical temperatures (T). Despite recent observations of superconductivity in nickel oxide-based compounds (the nickelates), evidence of Cooper pairing above 30 K in a system that is isostructural to the cuprates, but without copper, at ambient pressure and without lattice compression has remained elusive. Here we report superconductivity with a T approaching 40 K under ambient pressure in d hole-doped, late rare earth, infinite-layer nickel oxide (Sm-Eu-Ca-Sr)NiO thin films with negligible lattice compression, supported by observations of a zero-resistance state at 31 K and the Meissner effect.

Terahertz Spin-to-Charge Conversion in Strontium Iridate-Based Magnetic Heterostructures.

Oxide interfaces have enormous potential for future electronics with many applications, such as large spin Hall conductance, phase transitions, topological states, and superconductivity. However, previous investigations have predominantly focused on gigahertz frequencies; whilst the possibilities to fabricate devices operational at terahertz frequencies are demonstrated. A model solution is proposed employing 5d rare-earth, strontium iridate (SrIrO) heterostructure with cobalt (Co) ultrathin layers.