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Updated: May 16, 2026
06:42
Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
THz-driven nonlinear intersubband dynamics in quantum wells.
D Dietze1, J Darmo, K Unterrainer
1Photonics Institute, Vienna University of Technology 1040 Vienna, Austria. daniel.dietze@tuwien.ac.at
Optics Express
|November 29, 2012
Summary
We directly observed non-equilibrium intersubband dynamics in quantum wells using intense terahertz (THz) pulses. This revealed complex nonlinear optical effects beyond simple models, driven by broadband THz interactions.
Area of Science:
- Condensed Matter Physics
- Quantum Optics
- Materials Science
Background:
- Understanding light-matter interactions in quantum well structures is crucial for advanced optoelectronic devices.
- Standard models often simplify interactions to two-level systems, potentially missing complex dynamics in realistic scenarios.
- Modulation-doped multiple quantum wells offer a platform for exploring unique electronic and optical properties.
Purpose of the Study:
- To directly observe and characterize non-equilibrium intersubband dynamics in a quantum well system.
- To investigate nonlinear optical effects induced by intense, broadband terahertz (THz) pulses.
- To explore phenomena extending beyond the conventional two-level approximation of light-matter interaction.
Main Methods:
- Utilized intense single-cycle terahertz (THz) pulses with a multiple octave spanning bandwidth.
- Employed transmission spectroscopy to monitor changes in the quantum well sample.
- Analyzed the dependence of spectra on incident THz field strength to identify nonlinear effects.
Main Results:
- Demonstrated direct observation of non-equilibrium intersubband dynamics.
- Observed significant nonlinear optical effects, including efficient coherent population transfer.
- Showcased THz-induced undressing of collective excitations and the THz Stark effect due to phase-locked coupling of intersubband transitions.
Conclusions:
- Intense, broadband THz pulses can induce complex, non-equilibrium dynamics in quantum wells.
- The observed phenomena highlight the limitations of the two-level model for strong-field interactions.
- This work opens avenues for controlling quantum states and exploring novel light-matter interactions in nanostructures.
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