Abstract: Systems and techniques that facilitate precision-preserving qubit reduction based on spatial symmetries in fermionic systems are provided. In one or more embodiments, a symmetry component can generate a diagonalized second quantization representation of a spatial point group symmetry operation. The spatial point group symmetry operation can be associated with a molecule (e.g., a geometrical rotation, reflection, and/or inversion of a physical molecule that results in a new molecular orientation that is substantially the same as the original molecular orientation). In one or more embodiments, a transformation component can convert the diagonalized second quantization representation into a single Pauli string. In one or more embodiments, a tapering component can taper off qubits in a computational quantum algorithm that models properties of the molecule, based on the single Pauli string.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate estimation of an expected energy value of a Hamiltonian based on data of the Hamiltonian, the quantum state produced by a quantum device and/or entangled measurements are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a selection component that selects a quantum state measurement basis having a probability defined based on a ratio of a Pauli operator in a Hamiltonian of a quantum system. The computer executable components can further comprise a measurement component that captures a quantum state measurement of a qubit in the quantum system based on the quantum state measurement basis.

Abstract: Techniques regarding an iterative energy-scaled variational quantum eigensolver process are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a read-out component that determines a ground state energy value of a quantum Hamiltonian by employing a variational quantum eigensolver (VQE) algorithm, wherein VQE algorithm utilizes a symmetry that emerges at an energy scale of the quantum Hamiltonian.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate estimation of an expected energy value of a Hamiltonian based on data of the Hamiltonian, the quantum state produced by a quantum device and/or entangled measurements are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a selection component that selects a quantum state measurement basis having a probability defined based on a ratio of a Pauli operator in a Hamiltonian of a quantum system. The computer executable components can further comprise a measurement component that captures a quantum state measurement of a qubit in the quantum system based on the quantum state measurement basis.

Abstract: Techniques regarding a threshold scheme for quantum recommendation algorithms are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a quantum recommendation component that can project a preference vector onto a portion of a Hilbert space based on a value of a qubit phase register. The portion of the Hilbert space can encode singular values of a preference matrix that are greater than or equal to a defined threshold.

Abstract: A method for calculating excited state properties of a molecular system using a hybrid classical-quantum computing system includes determining, using a quantum processor and memory, a ground state wavefunction of a combination of quantum logic gates. In an embodiment, the method includes forming a set of excitation operators. In an embodiment, the method includes forming a set of commutators from the set of excitation operators and a Hamiltonian operator. In an embodiment, the method includes mapping the set of commutators onto a set of qubit states, the set of qubit states corresponding to a set of qubits of the quantum processor. In an embodiment, the method includes evaluating, using the quantum processor and memory, the set of commutators. In an embodiment, the method includes causing a quantum readout circuit to measure an excited state energy from the set of computed commutators.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate training of quantum Boltzmann machines by quantum imaginary-time evolution. According to an embodiment, a system can comprise computer executable components stored in memory. The computer executable components comprise an evaluation component that evaluates a Kullback-Leibler divergence gradient by a sampling procedure, where samples are generated by quantum imaginary-time evolution and a Hadamard circuit.

Abstract: Systems and techniques that facilitate max-cut approximate solution via quantum relaxation are provided. In various embodiments, a system can comprise a receiver component that can access a graph having a set of vertices and a set of edges. In various instances, the system can comprise a rounding component that can compute a max-cut approximate solution for the graph based on a quantum Hamiltonian relaxation of the graph.

Abstract: Techniques regarding quantum computation of molecular excited states are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise an initialization component that can categorize a plurality of excited operators from a mapped qubit Hamiltonian into sectors based on a commutation property of the plurality of excited operators with a symmetry from the mapped qubit Hamiltonian. The computer executable components can also comprise a matrix component that can generate an equation of motion matrix from an excited operator from the plurality of excited operators based on the sectors categorized by the initialization component.

Abstract: Techniques for quantum entanglement forging for quantum simulations are presented. A decomposer component can decompose a weakly entangled variational state into respective local components of the weakly entangled variational state, wherein the respective local components describe respective tensor product states. A quantum computing simulator component can perform respective quantum simulations of the respective local components of the weakly entangled variational state, and can determine respective portions of variational energy contributed by the respective tensor product states associated with the respective local components based on the respective quantum simulations of the respective local components of the weakly entangled variational state. An energy determination component can determine a variational energy associated with the weakly entangled variational state based on the respective portions of the variational energy contributed by the respective tensor product states.

Abstract: A method for bootstrapping a variational algorithm for quantum computing includes performing, using a quantum processor, a first iteration of a variational algorithm on a first wavefunction to compute a first expectation value of a first quantum system corresponding to a solution of the first iteration, the first wavefunction corresponding to a first quantum state of the first quantum system, the first expectation value comprising an energy of the first quantum state. The embodiment includes generating, based on the solution of the first iteration a second wavefunction as output of the first iteration of the variational algorithm, the second wavefunction corresponding to a second quantum state of the first quantum system.

Abstract: Techniques regarding an iterative energy-scaled variational quantum eigensolver process are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a read-out component that determines a ground state energy value of a quantum Hamiltonian by employing a variational quantum eigensolver (VQE) algorithm, wherein VQE algorithm utilizes a symmetry that emerges at an energy scale of the quantum Hamiltonian.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate state dependent calibration of qubit measurements are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a state prediction component that predicts a readout state of one or more qubits of a quantum circuit. The computer executable components can further comprise a calibration component that calibrates a qubit readout signal based on the readout state to generate a state dependent qubit readout signal to read the one or more qubits.

Abstract: Techniques regarding an iterative energy-scaled variational quantum eigensolver process are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a read-out component that determines a ground state energy value of a quantum Hamiltonian by employing a variational quantum eigensolver (VQE) algorithm, wherein VQE algorithm utilizes a symmetry that emerges at an energy scale of the quantum Hamiltonian.

Abstract: Techniques regarding quantum algorithm concatenation are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a concatenation component, operatively coupled to the processor, that can concatenate a first quantum algorithm and a second quantum algorithm by using an output of the first quantum algorithm as an initial parameter in the second quantum algorithm.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate estimation of an expected energy value of a Hamiltonian based on data of the Hamiltonian, the quantum state produced by a quantum device and/or entangled measurements are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a selection component that selects a quantum state measurement basis having a probability defined based on a ratio of a Pauli operator in a Hamiltonian of a quantum system. The computer executable components can further comprise a measurement component that captures a quantum state measurement of a qubit in the quantum system based on the quantum state measurement basis.

Abstract: Techniques regarding an iterative energy-scaled variational quantum eigensolver process are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a read-out component that determines a ground state energy value of a quantum Hamiltonian by employing a variational quantum eigensolver (VQE) algorithm, wherein VQE algorithm utilizes a symmetry that emerges at an energy scale of the quantum Hamiltonian.

Abstract: Systems and techniques that facilitate precision-preserving qubit reduction based on spatial symmetries in fermionic systems are provided. In one or more embodiments, a symmetry component can generate a diagonalized second quantization representation of a spatial point group symmetry operation. The spatial point group symmetry operation can be associated with a molecule (e.g., a geometrical rotation, reflection, and/or inversion of a physical molecule that results in a new molecular orientation that is substantially the same as the original molecular orientation). In one or more embodiments, a transformation component can convert the diagonalized second quantization representation into a single Pauli string. In one or more embodiments, a tapering component can taper off qubits in a computational quantum algorithm that models properties of the molecule, based on the single Pauli string.

Abstract: Techniques for performing cost function deformation in quantum approximate optimization are provided. The techniques include mapping a cost function associated with a combinatorial optimization problem to an optimization problem over allowed quantum states. A quantum Hamiltonian is constructed for the cost function, and a set of trial states are generated by a physical time evolution of the quantum hardware interspersed with control pulses. Aspects include measuring a quantum cost function for the trial states, determining a trial state resulting in optimal values, and deforming a Hamiltonian to find an optimal state and using the optimal state as a next starting state for a next optimization on a deformed Hamiltonian until an optimizer is determined with respect to a desired Hamiltonian.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate state dependent calibration of qubit measurements are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a state prediction component that predicts a readout state of one or more qubits of a quantum circuit. The computer executable components can further comprise a calibration component that calibrates a qubit readout signal based on the readout state to generate a state dependent qubit readout signal to read the one or more qubits.