Emerging probing perspective of two-dimensional materials physics: terahertz emission spectroscopy

Area of Science:

• Condensed Matter Physics
• Materials Science
• Optoelectronics

Background:

• Terahertz (THz) emission spectroscopy (TES) is a powerful tool for studying material photoelectric properties and nonlinear phenomena.
• Two-dimensional (2D) materials possess unique optoelectronic properties, driving innovation in flexible electronics, sensing, and nanoelectronics.
• 2D materials offer advantages like tunable bandgaps, high carrier mobility, and short carrier lifetimes, making them ideal for advanced applications.

Purpose of the Study:

• To review nonlinear processes in 2D materials investigated by TES.
• To showcase the diversity of TES applications in unraveling complex material properties.
• To discuss future advancements in THz generation and applications.

Main Methods:

• Investigating nonlinear processes in 2D materials using Terahertz emission spectroscopy (TES).
• Analyzing optical rectification, photon-drag, high-order harmonic generation, and spin-to-charge conversion in 2D materials.
• Reviewing applications of THz emission in 2D materials, including lasers, imaging, and biosensors.

Main Results:

• TES reveals rich information on photon, charge, phonon, and spin interactions in 2D materials, interfaces, and heterostructures.
• Nonlinear optical processes like optical rectification and photon-drag are key mechanisms for THz generation in 2D materials.
• Spintronic THz emitters offer unique advantages for future THz source development.

Conclusions:

• TES is crucial for fundamental understanding and application development of 2D materials.
• Advancements in THz generation mechanisms promise high-power, wide-bandwidth, and integrated THz sources.
• The integration of TES with 2D materials research will drive innovation in materials physics, optoelectronics, and post-Moore's era computing.