Natural Language Processing on Quantum Computers

The first real natural language processing algorithm to be run on a quantum computer was released in 2020, sparking great research interest. English sentences can be parsed according to grammatical rules. The meaning of a sentence is a function of its words' meanings and their grammatical relations. We compute this meaning using quantum circuits with two main parts: representing word meanings and applying grammatical relations. After optimizing circuit gate parameters with a machine learning method, the circuit predicts a truth value for the sentence. We give an example of this process, walking through the quantum circuit corresponding to the simple sentence "Romeo loves Juliet". We then discuss research extending this model to accomodate ambiguous words, in particular using mixed quantum states.