Simulating a perceptron on a quantum computer

• The perceptron is the basic computational unit of a neural network.
• Artificial neural networks find wide application in machine learning.
• We introduce a quantum circuit that simulates a classical perceptron efficiently.
• The quantum perceptron can process multiple inputs in superposition.
• It is a building block for quantum learning algorithms.

Perceptrons are the basic computational unit of artificial neural networks, as they model the activation mechanism of an output neuron due to incoming signals from its neighbours. As linear classifiers, they play an important role in the foundations of machine learning. In the context of the emerging field of quantum machine learning, several attempts have been made to develop a corresponding unit using quantum information theory. Based on the quantum phase estimation algorithm, this paper introduces a quantum perceptron model imitating the step-activation function of a classical perceptron. This scheme requires resources in O(n)O(n) (where n is the size of the input) and promises efficient applications for more complex structures such as trainable quantum neural networks.