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Long-Lived Population Inversion in Resonantly Driven Excitonic Antiferromagnet
Jacob A Warshauer1, Huyongqing Chen1, Daniel Alejandro Bustamante Lopez1
1Boston University, Department of Physics, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
Physical Review Letters
|February 6, 2025
Summary
Researchers discovered a long-lived photo-induced state in van der Waals magnets. This state, observed in NiPS3 with resonant pumping, exhibits negative photoconductivity and may enable terahertz lasing.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum optics
Background:
- Van der Waals magnets are a novel class of materials for studying light-matter interactions.
- Investigating spin-correlated excitations in these materials is crucial for next-generation electronics.
- Understanding photo-induced phenomena is key to novel optical applications.
Purpose of the Study:
- To discover and characterize photo-induced states in van der Waals antiferromagnets.
- To explore the potential of these states for applications like terahertz lasing.
- To investigate the dynamics and properties of light-matter interactions in NiPS3.
Main Methods:
- Utilizing resonant pumping at 1.476 eV on NiPS3.
- Measuring the lifetime of the photo-induced state using optical spectroscopy.
- Analyzing the photoconductivity response to identify population inversion.
Main Results:
- Discovery of a photo-induced state with a remarkably long lifetime of 17 picoseconds.
- The state appears exclusively under resonant pumping conditions in the antiferromagnetic state of NiPS3.
- Observed negative photoconductivity, indicative of population inversion.
Conclusions:
- The findings present a promising pathway towards achieving long-lived lasing at terahertz frequencies.
- Van der Waals magnets like NiPS3 offer a new platform for exploring exotic light-matter interactions.
- This research opens avenues for developing novel optoelectronic devices operating at terahertz frequencies.
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