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Table-top laser-based terahertz high harmonic generation spectroscopy under magnetic fields and low temperatures
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
The Review of Scientific Instruments
|October 23, 2024
Summary
We developed a terahertz (THz) nonlinear spectrometer for studying materials under extreme conditions. This powerful tool combines intense THz fields with high magnetic fields and low temperatures, enabling new insights into magnetic-field-dependent properties.
Area of Science:
- Condensed Matter Physics
- Spectroscopy
- Materials Science
Background:
- Terahertz (THz) spectroscopy is crucial for probing exotic quantum states in materials.
- Investigating materials under extreme conditions (low temperatures, high magnetic fields) reveals fundamental properties.
Purpose of the Study:
- To develop and demonstrate a novel THz nonlinear spectrometer capable of high magnetic fields and low temperatures.
- To enable detailed studies of magnetic-field-dependent phenomena in advanced materials.
Main Methods:
- A laser-driven intense THz source combined with a superconducting magnet (up to 10 T).
- Utilized tilted-pulse-front technique for THz generation and off-axis parabolic mirrors for focusing.
- Incorporated a motorized rotation stage for polarization-dependent measurements and a rotator for magnetic field geometry control.
Main Results:
- Achieved high electric fields (up to 500 kV/cm) at the THz focus.
- Successfully performed third harmonic generation (THG) measurements on the superconductor MgB2.
- Demonstrated THG dependence on temperature, sample angle, and magnetic field orientation (Faraday and Voigt geometries).
Conclusions:
- The developed THz spectrometer is a powerful instrument for exploring magnetic-field-dependent properties of materials.
- This setup opens new avenues for investigating quantum phenomena in condensed matter systems.
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