Abstract: This disclosure relates to a method for estimating a solution to a problem represented by a Hamiltonian on a quantum computer having a quantum state. A classical computer determines a trial state and evolves the quantum state of the quantum computer based on the trial state. The computer then determines estimates for expectation values with respect to the trial state of powers of the Hamiltonian based on measurements from the quantum computer and calculates an estimate of the solution based on the estimates for the expectation values of powers of the Hamiltonian for the trial state. The computer then repeated updates the trial state and repeats the measuring steps to iteratively improve the estimate of the solution.

Abstract: This disclosure relates to quantum computer arrays. In particular, a quantum processor comprises an array of source lines, drain lines and gate lines intersecting each other to define processor cells. Each of the processor cells comprise a first qubit, a second qubit and an electron confinement region disposed between the first qubit and the second qubit. A control circuit controls loading and unloading of an electron into the electron confinement region. The loading of the electron into the confinement region enables exchange interaction between electrons of the first qubit and the second qubit, and the unloading of the electron out of the electron confinement region suppresses exchange interaction between the electrons of the first qubit and the second qubit.

Abstract: The present disclosure provides a quantum processor realized in a semiconductor material and method to operate the quantum processor to implement adiabatic quantum computation. The quantum processor comprises a plurality of qubit elements disposed in a two-dimensional matrix arrangement. The qubits are implemented using the nuclear or electron spin of phosphorus donor atoms. Further, the processor comprises a control structure with a plurality of control members, each arranged to control a plurality of qubits disposed along a line or a column of the matrix. The control structure is controllable to perform adiabatic quantum error corrected computation.

Abstract: The present disclosure provides a quantum processor realized in a semiconductor material and method to operate the quantum processor to implement error corrected quantum computation. The quantum processor comprises a plurality of qubit elements disposed in a two-dimensional matrix arrangement. The qubits are implemented using the nuclear or electron spin of phosphorus donor atoms. Further, the processor comprises a control structure with a plurality of control members, each arranged to control a plurality of qubits disposed along a line or a column of the matrix. The control structure is controllable to perform topological quantum error corrected computation.

Abstract: The present disclosure provides a quantum processor realised in a semiconductor material and method to operate the quantum processor to implement adiabatic quantum computation. The quantum processor comprises a plurality of qubit elements disposed in a two-dimensional matrix arrangement. The qubits are implemented using the nuclear or electron spin of phosphorus donor atoms. Further, the processor comprises a control structure with a plurality of control members, each arranged to control a plurality of qubits disposed along a line or a column of the matrix. The control structure is controllable to perform adiabatic quantum error corrected computation.

Abstract: The present disclosure provides a quantum processor realised in a semiconductor material and method to operate the quantum processor to implement error corrected quantum computation. The quantum processor comprises a plurality of qubit elements disposed in a two-dimensional matrix arrangement. The qubits are implemented using the nuclear or electron spin of phosphorus donor atoms. Further, the processor comprises a control structure with a plurality of control members, each arranged to control a plurality of qubits disposed along a line or a column of the matrix. The control structure is controllable to perform topological quantum error corrected computation.