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15:47
Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
Gate-controlled spin-orbit interaction in a parabolic GaAs/AlGaAs quantum well
1IBM Research, Zurich Research Laboratory, Säumerstrasse 4, 8803 Rüschlikon, Switzerland. mattstud@phys.ethz.ch
Physical Review Letters
|August 8, 2009
Summary
We tuned spin-orbit interaction in a 2D electron gas using gate electrodes. The study monitored electron spin precession, finding tunable Rashba splitting but weak Dresselhaus splitting.
Area of Science:
- Condensed matter physics
- Spintronics
- Semiconductor heterostructures
Background:
- Spin-orbit interaction (SOI) is crucial for spintronics.
- Controlling SOI in two-dimensional electron gases (2DEGs) is key for device applications.
- Rashba and Dresselhaus effects are primary SOI mechanisms in 2DEGs.
Purpose of the Study:
- To investigate the tunability of spin-orbit interaction in a 2DEG.
- To differentiate and quantify Rashba and Dresselhaus spin splittings.
- To understand the impact of gate voltages on these SOI components.
Main Methods:
- Utilizing time-resolved Kerr rotation (TRKR) to monitor electron spin dynamics.
- Employing front and back gate electrodes to independently control carrier density and electric fields.
- Analyzing spin precession frequency to extract SOI parameters.
Main Results:
- Demonstrated independent tunability of Rashba spin splitting via gate biases.
- Observed a weakly gate-dependent Dresselhaus spin splitting.
- Determined the absolute values and signs of both Rashba and Dresselhaus components.
- Showcased the vanishing anisotropy of spin-dephasing rate at zero Rashba splitting.
Conclusions:
- Gate control offers a viable method for tuning SOI in 2DEGs.
- The interplay between Rashba and Dresselhaus effects significantly influences spin dynamics.
- Understanding these SOI components is essential for designing spintronic devices with tailored spin properties.
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