“…Initially, Kondacs and Watrous [8], and Moore and Crutchfield [9] proposed the concept of quantum automata separately. Since then, a variety of quantum automata models have been studied and demonstrated in various directions, such as QFAs, Latvian QFA, 1.5-way QFA, two-way QFA (2QFA), quantum sequential machine, quantum pushdown automata, quantum Turing machine, quantum multicounter machines, quantum queue automata [10], quantum multihead finite automata, QFAs with classical states (2QCFA) [11,12], state succinctness of two-way probabilistic finite automata (2PFA), QFA, 2QFA, and 2QCFA [13][14][15], interactive proof systems with QFAs [16,17], quantum finite state machines of matrix product state [18], promise problems recognition by QFA [19][20][21][22], quantum-omega automata [23] and semi-quantum two-way finite automata [24][25][26], time complexity advantages of QFA [27], nonuniform classes of polynomial size QFA [28,29], QFA and linear temporal logic relationship [30], and many more since the past 2 decades [31][32][33][34]. These models are effective in determining the boundaries of various computational features and expressive power [35][36][37].…”