We report on AlGaN/GaN multi-quantum-well structures displaying intersubband absorption in the THz spectral range. Firstly, we theoretically analyze the weaknesses of the state-of-the-art GaN-based step-quantum-well architecture from an optoelectronic standpoint. We then propose a modified geometry with improved structural robustness considering the uncertainties associated to the growth. This ...

A bilayer electron system that is formed in a 60-nm-wide GaAs quantum well and has large difference of the densities layers been studied. It found that, when magnetic field tilted from normal to plane system, integer Hall effect states at filling factors Landau levels 1 2 disappear; instead, fractional interval between these appear ν F = 4/3, 10/7, 6/5 with odd denominators factor 5/4. Several ...

Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation, secure twoand multi-party computation and delegated quantum computation. Quantum cryptography also st...