Fault-tolerant design of shift register using multilayer crossover in QCA Vaibhav Jain, Devendra Kumar Sharma and Hari Mohan Gaur Eur. Phys. J. Plus, 138 5 (2023) 453 Published online: 24 May 2023 DOI: 10.1140/epjp/s13360-023-04035-9