Method for determining a quantum phase parameter of a solid-state material sample and apparatus for implementing the same

A quantum computer apparatus, the apparatus comprising a quantum processor and a memory operatively coupled to the processor, wherein the apparatus is configured to implement, using the quantum processor, a method for determining a quantum phase parameter characterizing a property of a quantum phase of a solid-state material sample, the method comprising:

• Determining, for a bath site of an impurity-bath model of the solid-state material sample comprising one or more impurity sites representing an impurity and one or more bath sites representing a bath, respective parameters Vp and εp of the bath site of index p, wherein Vp represents a strength of a coupling between the bath site of index p and the impurity, and εp represents an energy of the bath site of index p;
• Configuring a quantum circuit for computing a Green's function of the solid-state material sample corresponding to the impurity-bath model, wherein one or more quantum gates of the quantum circuit are configured based on the determined respective parameters Vp and εp, wherein the quantum circuit is configured to use one or more noisy qubits, and wherein respective amplitude damping noise patterns of the noisy qubits are used to represent dissipation of the impurity-bath model;
• and
• Executing, on a quantum computer, the quantum circuit to determine an estimate of the quantum phase parameter.

A non-transitory computer-readable medium encoded with executable instructions which, when executed, causes an apparatus comprising a processor operatively coupled with a memory, to perform a method for determining a quantum phase parameter characterizing a property of a quantum phase of a solid-state material sample, the method comprising:

• Determining, for a bath site of an impurity-bath model of the solid-state material sample comprising one or more impurity sites representing an impurity and one or more bath sites representing a bath, respective parameters Vp and εp of the bath site of index p, wherein Vp represents a strength of a coupling between the bath site of index p and the impurity, and εp represents an energy of the bath site of index p;
• Configuring a quantum circuit for computing a Green's function of the solid-state material sample corresponding to the impurity-bath model, wherein one or more quantum gates of the quantum circuit are configured based on the determined respective parameters Vp and εp, wherein the quantum circuit is configured to use one or more noisy qubits, and wherein respective amplitude damping noise patterns of the noisy qubits are used to represent dissipation of the impurity-bath model;
• and
• Executing, on a quantum computer, the quantum circuit to determine an estimate of the quantum phase parameter.