Limits of adiabatic clocking in quantumdot cellular automata
Abstract
Ultimate bounds on the maximum operating frequency of networks of Quantumdot Cellular Automata (QCA) devices have yet to be established. We consider the adiabaticity of such networks in the twostate approximation where clocking is achieved via modulation of the interdot tunneling barriers. Estimates of the maximum operating frequency that would allow a 99% probability of observing the correct logical output are presented for a subset of the basic components used in QCA network design. Simulations are performed both in the coherent limit and for a simple dissipative model. We approach the problem of tunnelbased clocking from the perspective of quantum annealing and present an improved clocking schedule allowing for faster operation. Using an analytical solution for driven QCA wires, we show that the maximum operating frequency in the coherent limit falls off with the square of the wire length, potentially limiting the size of clocked regions.
 Publication:

Journal of Applied Physics
 Pub Date:
 February 2020
 DOI:
 10.1063/1.5135308
 arXiv:
 arXiv:1911.00122
 Bibcode:
 2020JAP...127e4502R
 Keywords:

 Quantum Physics
 EPrint:
 14 pages, 21 figures