Patent ID: 11934464
Assignee: MULTIVERSE COMPUTING S.L.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method for performing unsupervised clustering of a data set comprising a plurality of data points, comprising the following steps:
a data set importing step wherein a classical digital computer imports the plurality of data points of the data set;
a data point locating step wherein the classical digital computer locates the plurality of data points on the surface of a unique Bloch sphere, the position of each data point on the Bloch sphere being identified by a corresponding initial position vector in the Bloch sphere, the Bloch sphere representing a qubit, and the initial position vector of each data point on the Bloch sphere representing a quantum state of the qubit;
a cost function definition step wherein a cost function is defined, the cost function having its minimum cost when the data points are clustered optimally, the cost function comprising a plurality of sets of variational parameters, each set of variational parameters comprising at least one group of three variational parameters, and the plurality of sets of variational parameters being common to all the data points;
an initial cost function calculation step wherein the classical digital computer calculates the cost of the cost function based on the initial position vector of each data point of the data set;
a cost function minimization step comprising the following steps which are repeated until the cost function reaches its minimum cost:
a classical optimizer execution step wherein the classical digital computer executes a classical optimizer for the cost function, obtaining a plurality of sets of optimized variational parameters;
an optimized variational parameter sending step wherein the classical digital computer sends the plurality of sets of optimized variational parameters to a quantum computer, the quantum computer clustering the plurality of data points using as many qubits as the number of sets of variational parameters in the cost function and comprising a quantum circuit configured for performing a plurality of operations on said qubits; and
a data point processing step comprising the following steps which are repeated for each data point in the data set:
an initial position vector sending step wherein the classical digital computer sends the initial position vector of each data point of the data set to the quantum computer;
an initial position vector translation step wherein the quantum computer translates said initial position vector into a corresponding initial quantum state of a qubit, and initializes the plurality of qubits in the quantum circuit in said initial quantum state;
a quantum circuit execution step wherein the quantum computer implements the quantum circuit, the quantum circuit comprising as many layers on each qubit as the number of groups of three variational parameters in the corresponding set of variational parameters, each layer modifying the quantum state of the corresponding qubit based on the values of the three optimized variational parameters in each group, and the last layer on each qubit modifying the quantum state of said qubit to a final quantum state, the plurality of qubits in the quantum circuit being entangled, and
a quantum state sending step wherein the quantum computer measures and sends the final quantum state of the qubits in the quantum circuit and the probability of said qubits being in said final quantum state to the classical digital computer, the final quantum state of the qubits in the quantum circuit corresponding to a label in which the corresponding data point is located;

a cost function calculation step wherein the classical digital computer calculates the cost of the cost function based on the final quantum state of the qubits in the quantum circuit of all the data points of the data set and the probability of said qubits being in said final quantum state.