One-dimensional quantum wire formed at the boundary between two insulating LaAlO3/SrTiO3 interfaces.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Two-dimensional (2D) interfaces, such as those formed by LaAlO3/SrTiO3, exhibit complex electronic properties.
• Understanding the behavior of charge carriers at these interfaces is crucial for developing novel electronic devices.

Purpose of the Study:

• To engineer and investigate the electronic properties of a novel tiled structure of 2D LaAlO3/SrTiO3 interfaces.
• To explore the nature of conductance at the boundaries between tiled structures and its dependence on gate voltage.

Main Methods:

• Fabrication of a tiled structure using alternating one and three unit cells of LaAlO3 on SrTiO3.
• Low-temperature electrical transport measurements to probe conductance.
• Gate voltage modulation to study the conductance characteristics.

Main Results:

• Observation of a conducting boundary between adjacent tiles of the LaAlO3/SrTiO3 structure.
• Quantized steps in conductance as a function of gate voltage at low temperatures, suggesting a one-dimensional channel.
• The conductance step size was found to be half the quantum of conductance, providing evidence for the absence of spin degeneracy.

Conclusions:

• The engineered tiled interface structure supports one-dimensional conducting channels.
• The observed quantized conductance and its step size reveal the absence of spin degeneracy, offering insights into spin-related phenomena in 2D electron systems.