Abstract: Methods and apparatus are disclosed, including an example of a method of determining a distance between a first point and a second point. The method includes manipulating quantum states of at least first and second qubits of a quantum computing device based on a test vector representing the first point and a training vector representing the second point, performing quantum interference between the test vector and the training vector, performing a measurement on one or more of the qubits to determine the distance, and determining the distance from the measurement.

Abstract: A method of method of classifying data is disclosed. The method comprises manipulating quantum states of qubits of a quantum computing device based on a first copy of a test vector, a second copy of the test vector, a first training vector and a second training vector, so as to load a modified first copy of the test vector, a modified second copy of the test vector, a modified first training vector and a modified second training vector onto the quantum computing device, wherein the magnitude of the angle between the modified first copy of the test vector and the modified first training vector is equal to the magnitude of the angle between the first copy of the test vector and the first training vector, and where the magnitude of the angle between the modified second copy of the test vector and the modified second training vector is equal to the magnitude of the angle between the second copy of the test vector and the second training vector.

Abstract: Methods and apparatus are disclosed, including an example of a method of determining a distance between a first point and a second point. The method includes manipulating quantum states of at least first and second qubits of a quantum computing device based on a test vector representing the first point and a training vector representing the second point, performing quantum interference between the test vector and the training vector, performing a measurement on one or more of the qubits to determine the distance, and determining the distance from the measurement.