Quantum random walks do not need a coin toss

Apoorva Patel, K. S. Raghunathan, Pranaw Rungta
2005 Physical Review A. Atomic, Molecular, and Optical Physics  
Classical randomized algorithms use a coin toss instruction to explore different evolutionary branches of a problem. Quantum algorithms, on the other hand, can explore multiple evolutionary branches by mere superposition of states. Discrete quantum random walks, studied in the literature, have nonetheless used both superposition and a quantum coin toss instruction. This is not necessary, and a discrete quantum random walk without a quantum coin toss instruction is defined and analyzed here. Our
more » ... construction eliminates quantum entanglement from the algorithm, and the results match those obtained with a quantum coin toss instruction.
doi:10.1103/physreva.71.032347 fatcat:h3fl5tzp2fgsxi3qvloiagcdmy