3,736 research outputs found
Strain-driven light polarization switching in deep ultraviolet nitride emitters
Residual strain plays a critical role in determining the crystalline quality
of nitride epitaxial layers and in modifying their band structure; this often
leads to several interesting physical phenomena. It is found, for example, that
compressive strain in AlxGa1-xN layers grown on AlyGa1-yN (x<y) templates
results in an anti-crossing of the valence bands at considerably much higher Al
composition than expected. This happens even in the presence of large and
negative crystal field splitting energy for AlxGa1-xN layers. A judicious
magnitude of the compressive strain can support vertical light emission (out of
the c-plane) from AlxGa1-xN quantum wells up to x\approx 0.80, which is
desirable for the development of deep ultraviolet light-emitting diodes
designed to operate below 250nm with transverse electric polarization
characteristics
Resistively detected nuclear magnetic resonance via a single InSb two-dimensional electron gas at high temperature
We report on the demonstration of the resistively detected nuclear magnetic
resonance (RDNMR) of a single InSb two-dimensional electron gas (2DEG) at
elevated temperatures up to 4 K. The RDNMR signal of 115In in the simplest
pseudospin quantum Hall ferromagnet triggered by a large direct current shows a
peak-dip line shape, where the nuclear relaxation time T1 at the peak and the
dip is different but almost temperature independent. The large Zeeman,
cyclotron, and exchange energy scales of the InSb 2DEG contribute to the
persistence of the RDNMR signal at high temperatures.Comment: 11pages,3figure
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