Nanoscale Distortions of Si Quantum Wells in Si/SiGe Quantum-Electronic Heterostructures



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Si quantum wells on plastically relaxed SiGe substrates have nanometer variations in crystallographic parameters crucial to quantum-information devices. Synchrotron X-ray nanodiffraction shows that the lattice of the Si quantum well varies in orientation and thickness over lateral distances of 100 nm to 1 μm. The result is that the energy levels of the confined states are shifted by energies similar to the electron temperature.