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Deterministic optical polarisation in nitride quantum dots at thermoelectrically cooled temperatures
Tong Wang1, Tim J Puchtler1, Saroj K Patra2,3
1Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK.
Scientific Reports
|September 23, 2017
Summary
Solid-state quantum dots achieve intrinsic optical polarization control at thermoelectrically cooled temperatures. This robust control, nearly insensitive to temperature variations, enables new on-chip quantum dot applications.
Area of Science:
- Materials Science
- Quantum Physics
- Optoelectronics
Background:
- Solid-state quantum dots are promising for quantum technologies.
- Controlling optical polarization is crucial for many quantum applications.
- Temperature sensitivity of quantum dot properties can limit their use.
Purpose of the Study:
- To demonstrate intrinsic optical polarization control in quantum dots.
- To investigate the temperature dependence of polarization properties.
- To elucidate the fundamental origins of polarization behavior.
Main Methods:
- Growth of non-polar Indium Gallium Nitride (InGaN) quantum dots.
- Experimental measurements of polarization degree from cryogenic to 200 K.
- Theoretical modeling using Fermi-Dirac statistics and k·p theory.
Main Results:
- Achieved intrinsic optical polarization control in quantum dots at ≥200 K.
- Observed stable polarization degree (~0.90) below 100 K, decreasing slowly to 0.77 at 200 K.
- Demonstrated temperature-insensitive polarization axis determined by crystallography.
Conclusions:
- Intrinsic optical polarization control is feasible in solid-state quantum dots at thermoelectrically cooled temperatures.
- The observed robust polarization properties are explained by quantum dot anisotropy and Fermi-Dirac statistics.
- This work paves the way for polarization-based quantum dot applications in on-chip devices.
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