A method for identifying an excited energy state of a system of interacting electrons, comprising providing a first quantum circuit defined by a generator function and providing a second quantum circuit defined by a discriminator function. The method comprises optimising the values of the set of parameters θ of the generator function to substantially minimise the energy of the state generated by the first quantum circuit, and to substantially minimise the extent of overlap of the state generated by the first quantum circuit and each known valid state of the system. The method further comprises, cooperatively, training the discriminator function by optimising the value of the set of parameters ϕ of the discriminator function, to train the discriminator function to discriminate between the state generated by the first quantum circuit and each of the known valid states of the system. The optimised values of the set of parameters θ of the generator function correspond to values parametrising the generator function for generating the next excited energy state of the system of interacting electrons.
Claim CLM-00001. 1. A method for identifying an excited energy state of a system of interacting electrons, comprising:
providing a first quantum circuit, the first quantum circuit defined by a generator function parameterised by a set of parameters, θ, wherein applying the first quantum circuit to a set of qubits in an initial state generates a state of the system represented by a wavefunction, Ψ; providing n sets of values θn−1 for the set of parameters, θ, wherein each set of values θn−1 generates an nth valid energy state of the system represented by a wavefunction, Ψn−1, wherein n is one or more; providing a second quantum circuit, the second quantum circuit defined by a discriminator function parameterised by a set of parameters, ϕ, wherein applying the second quantum circuit to the set of qubits in the state of the system represented by the wavefunction, provides an output representing an extent of overlap of the wavefunction with the wavefunction Ψn−1 of each of the n known valid states of the system; optimising the values of the set of parameters θ to substantially minimise the energy of the state generated by the first quantum circuit represented by the wavefunction Ψ, and to substantially minimise the extent of overlap of the state generated by the first quantum circuit represented by the wavefunction and each of the n known valid states of the system represented by respective wavefunction Ψn−1; and cooperatively, training the discriminator function by optimising the value of the set of parameters ϕ to train the discriminator function to discriminate between the wavefunction Ψ of the state generated by the first quantum circuit and the wavefunction Ψn−1 representing each of the n valid states of the system; wherein the optimised values of the set of parameters θ correspond to a set of values θn parametrising the generator function defining the first quantum circuit for generating an n+1th valid energy state of the system represented by wavefunction, Ψn, which is an excited energy state of the system of interacting electrons.
Claim CLM-00012. 12. A computing apparatus for identifying an excited energy state of a system of interacting electrons, comprising:
a classical computer; and a quantum computer comprising a set of qubits, the quantum computer configured to apply a first quantum circuit the first quantum circuit defined by a generator function parameterised by a set of parameters, θ, wherein applying the first quantum circuit to a set of qubits in an initial state generates a state of the system represented by a wavefunction, Ψ, and to apply a second quantum circuit defined by a discriminator function parameterised by a set of parameters, ϕ, wherein applying the second quantum circuit to the set of qubits in a state of the system represented by a wavefunction, Ψ provides an output representing an extent of overlap of the wavefunction Ψ with the wavefunction Ψn−1 of each of the n known valid states of the system, wherein each of the n known valid states of the system are parametrised by a set of values θn−1 for the set of parameters, θ; wherein the computing apparatus is configured to optimise the values of the set of parameters θ to substantially minimise the energy of the state generated by the first quantum circuit represented by the wavefunction Ψ, and to substantially minimise the extent of overlap of the state generated by the first quantum circuit represented by the wavefunction Ψ and each of the n known valid states of the system represented by respective wavefunction Ψn−1; and cooperatively, to train the discriminator function by optimising the value of the set of parameters ϕ to train the discriminator function to discriminate between the wavefunction of the state generated by the first quantum circuit and the wavefunction Ψn−1 representing each of the n valid states of the system; wherein the optimised values of the set of parameters θ correspond to a set of values θn parametrising the generator function defining the first quantum circuit for generating an n+1th valid energy state of the system represented by wavefunction, Ψn, which is an excited energy state of the system of interacting electrons.
Claim CLM-00018. 18. (canceled)
Claim CLM-00021. 21. A method for identifying an excited energy state of a system of interacting electrons on a hybrid classical and quantum computer processing unit, comprising:
optimisation of a cooperating generator and discriminator function to generate a set of parameters for the generator function representing an excited energy state of the system which has minimum energy and which also has minimum overlap with a predefined ground energy state.
