A quantum contextual measurement is generated from a quantum device capable of performing continuous time evolution, by generating a first measurement result and a second measurement result and combining the first measurement result and the second measurement result to generate the quantum contextual measurement. The first measurement result may be generated by initializing the quantum device to a first initial quantum state, applying a first continuous time evolution to the first initial state to generate a first evolved state, and measuring the first evolved state to generate the first measurement result. A similar process may be applied to generate a second evolved state which is at least approximately equal to the first evolved state, and then applying another continuous time evolution to the second evolved state to generate a third evolved state, and measuring the third evolved state to generate the second measurement result.

Aspects of the present disclosure describe a method including compressing and uncompressing redundant quantum information encoded in quantum computers; processing quantum information in the compressed space; and computing, in response to determining the ansatz terms, a set of optimal transformations.

Aspects of the present disclosure describe a method including compressing and uncompressing redundant quantum information encoded in quantum computers; processing quantum information in the compressed space; and computing, in response to determining the ansatz terms, a set of optimal transformations.

Quantum computing systems and methods are provided. In one example, a quantum computing system includes a quantum system having one or more quantum system qubits and one or more ancilla qubits. The quantum computing system includes one or more quantum gates implemented by the quantum computing system. The quantum gate(s) are operable to configure the one or more ancilla qubits into a known state. The quantum computing system includes a quantum measurement circuit operable to perform a plurality of measurements on the one or more quantum system qubits using the one or more ancilla qubits. The quantum computing system includes one or more processors operable to determine a reduced density matrix for a subset of the quantum system based on a set of the plurality of measurements that include a number of repeated measurements performed using the quantum measurement circuit.

A quantum chemistry method includes causing display, via a processor, of a representation of a plurality of controlled single-excitation quantum gates. A selection of a subset of controlled single-excitation quantum gates from the plurality of controlled single-excitation quantum gates is received at the processor. A particle-preserving unitary for a quantum chemistry simulation is identified based on the selected subset of controlled single-excitation quantum gates. At least one controlled single-excitation quantum gate from the plurality of controlled single-excitation quantum gates can be configured to apply a Givens rotation.

A quantum chemistry method includes causing display, via a processor, of a representation of a plurality of controlled single-excitation quantum gates. A selection of a subset of controlled single-excitation quantum gates from the plurality of controlled single-excitation quantum gates is received at the processor. A particle-preserving unitary for a quantum chemistry simulation is identified based on the selected subset of controlled single-excitation quantum gates. At least one controlled single-excitation quantum gate from the plurality of controlled single-excitation quantum gates can be configured to apply a Givens rotation.

Disclosed is a minimum searching method for searching a minimum in N (N is a natural number) data by a computing device including at least one processor. The method for searching the minimum may include: determining a threshold; initializing Qubits to include indexes representing addresses in which the N data are recorded, respectively, and the threshold in a superposition state; returning, from a superposition-state index, superposition-state data corresponding to the superposition-state index through a quantum memory; comparing the superposition-state data with the threshold in parallel through a quantum comparator (Q-comp); and searching the minimum based on the comparison result.

Disclosed is a minimum searching method for searching a minimum in N (N is a natural number) data by a computing device including at least one processor. The method for searching the minimum may include: determining a threshold; initializing Qubits to include indexes representing addresses in which the N data are recorded, respectively, and the threshold in a superposition state; returning, from a superposition-state index, superposition-state data corresponding to the superposition-state index through a quantum memory; comparing the superposition-state data with the threshold in parallel through a quantum comparator (Q-comp); and searching the minimum based on the comparison result.

The disclosure describes various aspects related to enabling effective multi-qubit operations, and more specifically, to techniques for enabling parallel multi-qubit operations on a universal ion trap quantum computer. In an aspect, a method of performing quantum operations in an ion trap quantum computer or trapped-ion quantum system includes implementing at least two parallel gates of a quantum circuit, each of the at least two parallel gates is a multi-qubit gate, each of the at least two parallel gates is implemented using a different set of ions of a plurality of ions in a ion trap, and the plurality of ions includes four or more ions. The method further includes simultaneously performing operations on the at least two parallel gates as part of the quantum operations. A trapped-ion quantum system and a computer-readable storage medium corresponding to the method described above are also disclosed.

Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.