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Observation of Circular Dichroism Induced by Electronic Chirality
Qian Xiao1, Oleg Janson2, Sonia Francoual3
1International Center for Quantum Materials, School of Physics, <a href="https://ror.org/02v51f717">Peking University</a>, Beijing 100871, China.
Physical Review Letters
|October 7, 2024
Summary
Researchers found evidence of intrinsic electronic chirality in 1T-TiSe2 using resonant elastic x-ray scattering. This discovery opens new avenues for manipulating chiral matter without structural or magnetic handedness.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Chiral phases of matter are common in nature, exhibiting handedness in structures like quartz and magnetic materials.
- 1T-TiSe2 exhibits unique chirality originating from electronic charge and orbital fluctuations, distinct from classical examples.
- Previous studies lacked direct bulk evidence for intrinsic broken inversion symmetry and chirality in 1T-TiSe2.
Purpose of the Study:
- To provide direct bulk evidence for intrinsic chirality in 1T-TiSe2.
- To investigate the nature of chirality arising from electronic charge and orbital fluctuations.
- To establish resonant elastic x-ray scattering (REXS) as a sensitive probe for electronic chirality.
Main Methods:
- Resonant elastic x-ray scattering (REXS) technique.
- Analysis of circular dichroism at forbidden Bragg peaks.
- Comparison of experimental data with calculated scattering intensities.
Main Results:
- Observed significant circular dichroism (up to ~40%) at forbidden Bragg peaks associated with charge and orbital ordering in 1T-TiSe2.
- Demonstrated that the observed dichroism is dependent on incident energy and azimuthal angle.
- Attributed the origin of the dichroism to bulk chiral electronic order within 1T-TiSe2.
Conclusions:
- Confirmed the presence of intrinsic bulk chiral electronic order in 1T-TiSe2.
- Established REXS as a powerful and sensitive method for detecting and characterizing electronic chirality.
- Opened possibilities for manipulating chirality in quantum materials without external structural or magnetic fields.
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