Figure 12
From: Practical overview of image classification with tensor-network quantum circuits

A tree tensor quantum circuit with \(n_V=1\) and two entangling layers applied to four qubits. Single-qubit gates apply arbitrary Bloch rotations of user-defined value \(\omega\) in the Z axis, \(\theta\) in the Y axis, and \(\phi\) in the X axis. These rotations can be optimized such that the circuit classifies \(16\times 16\) pixel images. The circuit can also be extended to more qubits, enabling the classification of larger images.