Abstract: The is provided a computer-implemented method for generating a quantum circuit from a Unitary Coupled Cluster (UCC) Ansatz, wherein the Ansatz represents an excitation of a reference state by a parameterised operator including excitation operators, and wherein the Ansatz includes multi-qubit Pauli operators that are determined from each excitation operator. The method comprises: partitioning the Pauli operators into mutually commuting sets and sequencing the Pauli operators by set; generating Pauli gadgets from the Pauli operators by Trotterization, wherein the Pauli gadgets have a same sequencing by set as the Pauli operators; diagonalising each set of Pauli gadgets to convert the Pauli gadgets into phase gadgets; and transforming the phase gadgets into one- and two-qubit native gates to generate the quantum circuit. Moreover, there is also provided a system that is configured to implement the method.

Abstract: Concepts, systems and methods are described for generating a quantum circuit from a Unitary Coupled Cluster (UCC) ansatz which represents the excitation of a reference state by a parameterised operator including excitation operators. The UCC ansatz includes multi-qubit Pauli operators, referred to as Pauli strings, determined from each excitation operator. The method comprises partitioning the Pauli strings into mutually commuting sets and sequencing the Pauli strings by set. Pauli gadgets are then generated from the Pauli strings by Trotterization, the Pauli gadgets having the same sequencing by set as the Pauli strings. Each set of Pauli gadgets is diagonalised to convert the Pauli gadgets into phase gadgets which are then transformed into one- and two-qubit native gates to generate the quantum circuit.

Abstract: Concepts, systems and methods are described for generating a quantum circuit from a Unitary Coupled Cluster (UCC) ansatz which represents the excitation of a reference state by a parameterised operator including excitation operators. The UCC ansatz includes multi-qubit Pauli operators, referred to as Pauli strings, determined from each excitation operator. The method comprises partitioning the Pauli strings into mutually commuting sets and sequencing the Pauli strings by set. Pauli gadgets are then generated from the Pauli strings by Trotterization, the Pauli gadgets having the same sequencing by set as the Pauli strings. Each set of Pauli gadgets is diagonalised to convert the Pauli gadgets into phase gadgets which are then transformed into one- and two-qubit native gates to generate the quantum circuit.