We have studied the utility of making use of bases that are not unbiased . The utility of this study is that it has been commonly believed that an efficient QKD system must use two or more mutually unbiased bases. We have studied the possibility of intentionally using states spaces that are not mutually unbiased, and we have found that this situation can be helpful in mitigating the problem of state-dependent diffraction and also in simplifying some of the laboratory setup for producing qudit states and for measuring them.
1. High-dimensional quantum key distribution based on mutually partially unbiased bases, F. Wang, P. Zeng, J. Zhao, B. Braverman, Y. Zhou, M. Mirhosseini, X. Wang, H. Gao, F. Li, R. W. Boyd, and P. Zhang, Phys. Rev. A 101, 032340 (2020).