Abstract: Error detection and correction in a quantum computer are provided. The quantum computer includes qubits encoding a plurality of data qudits and an ancilla qudit. The qubits encoding the plurality of data qudits are arranged into a grouping wherein the qubits encoding each of the data qudits are within an interaction distance of an interacting state of the qubits encoding the ancilla qudit. A leakage error of a first data qudit of the plurality of data qudits into the interacting state is detected by detecting a state of the ancilla qudit. Quantum states of the qudits are selected such that angular momentum selection rules prohibit mixing between the selected quantum states during a leakage error of one of the qudits into a noninteracting state. The leakage error is corrected by optical pumping of the noninteracting state, preserving coherence of the selected quantum states in the absence of the leakage error.

Abstract: Systems and methods for quantum convolutional neural networks are described. Systems and methods can apply convolving and pooling layers to input qudits. The qudits can be measured to identify information about the input qudits. Systems and methods can also apply quantum convolutional neural network encoding and decoding techniques for quantum error correction.