Enormous Lifetime Variations and Anomalous Nonlinear Dynamics of Interlayer Excitons in Reconstructed MoSe2/WSe2
Mainak Mondal1, Kenji Watanabe2, Takashi Taniguchi3
1Department of Physics, Indian Institute of Science, Bengaluru 560012, India.
Nano Letters
|March 31, 2026
Summary
Quantum confinement persists in twisted transition metal dichalcogenide heterostructures, creating unique interlayer exciton states. These exhibit varied lifetimes and nonlinear dynamics, offering potential for novel sensing applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Twisted transition metal dichalcogenide heterostructures form mesoscopic domains with altered potential landscapes.
- Interlayer excitons in these domains show strong many-body interactions, but quantum confinement effects are not fully understood.
Purpose of the Study:
- To investigate the persistence and impact of quantum confinement on interlayer exciton dynamics in reconstructed domains.
- To explore the nonlinear dynamics of these excitons under high excitation.
Main Methods:
- Time-resolved photoluminescence spectroscopy.
- Theoretical calculations.
Main Results:
- Quantum confinement is confirmed in flat, reconstructed regions of twisted heterostructures.
- Multiple, closely spaced interlayer exciton states (∼1 meV) with vastly different lifetimes (sub-ns to >100 ns) were observed.
- Cascade-like transitions and anomalous nonlinear dynamics, termed 'quantum siphoning', were identified.
Conclusions:
- Reconstructed domains act as potential wells, supporting quantum confinement and influencing exciton dynamics.
- Nonlinear dynamics and quantum confinement extend beyond the ideal moiré model.
- Findings suggest potential applications in sensing and strain-engineered dynamics modification.
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