Observation of quantum confinement by strain gradients

We have created one-dimensional quantum wells (quantum wires) by laterally straining a GaAs quantum well with patterned carbon stressors 180 nm in width. We find four well-resolved one-dimensional subbands in the excitation spectra, whose constant spacing of 2.4 meV confirms quantitatively that there is quantum confinement in the parabolic well predicted by continuum elasticity theory. The lateral width of the electron ground state is 35 nm.