Quantum State Transfer and Periodicity in Discrete‐Time Quantum Walks Under Non‐Markovian Dephasing Noise

ABSTRACT In quantum communication, quantum state transfer from one location to another in a quantum network plays a prominent role, where the impact of noise could be crucial. The idea of state transfer can be fruitfully associated with quantum walk on graphs. We investigate the consequences of non‐Markovian quantum noises on periodicity and state transfer induced by a discrete‐time quantum walk on graphs, governed by the Grover coin operator. Different bipartite graphs, such as the path graph, cycle graph, star graph, and complete bipartite graph, present periodicity and state transfer in a discrete‐time quantum walk depending on the topology of the graph. We investigate the effect of quantum non‐Markovian dephasing noises, particularly quantum non‐Markovian Random Telegraph Noise (RTN) and modified non‐Markovian Ornstein‐Uhlenbeck Noise (OUN) on state transfer and periodicity. We demonstrate how the RTN and OUN noises allow state transfer and periodicity for a finite number of steps in a quantum walk. Our investigation brings out the feasibility of state transfer in a noisy environment.