Search All Patents in Quantum Computing
Patent US10622978
Issued 2020-04-14
Quantum Logic Gate Design And Optimization
A method of performing an entangling operation in a chain of trapped ions includes selecting a gate duration value and a detuning value of a pulse sequence used to perform an entangling gate operation on a first ion and a second ion, measuring frequencies of collective motional modes of the chain, computing a value of an entangling interaction between the first and second ions and values of phase space trajectories of the collective motional modes, based on the selected gate duration value, the selected detuning value, and the measured frequencies of the collective motional modes, determining an intensity of each pulse segment in the pulse sequence based on the computed values, generating the pulse sequence by connecting the pulse segments, each pulse segment having the determined intensity and a pulse shape with ramps formed using a spline, and applying the generated pulse sequence to the first and second ions.
Much More than Average Length Specification
View the Patent Matrix® Diagram to Explore the Claim Relationships
USPTO Full Text Publication >
- 1. A method of performing an entangling operation between two trapped ions in a quantum computer comprising:
selecting a gate duration value and a detuning value of a pulse sequence used to perform an entangling gate operation on a first ion and a second ion in a chain of trapped ions, each of the trapped ions having two frequency-separated states defining a qubit, wherein the pulse sequence comprises a plurality of pulse segments; measuring frequencies of collective motional modes of the chain of trapped ions in a direction perpendicular to a direction that the chain of trapped ions are aligned; computing a value of an entangling interaction between the first and second ions and computing values of phase space trajectories of the collective motional modes for the first and second ions based on the selected gate duration value, the selected detuning value, and the measured frequencies of the collective motional modes; determining an intensity of each of the plurality of pulse segments based on the computed values of the entanglement interaction and the computed values of the phase space trajectories; generating the pulse sequence by connecting the plurality of pulse segments, each of the plurality of pulse segments having the determined intensity and a pulse shape with ramps formed using a spline at a start and an end of each of the plurality of pulse segments; and applying the generated pulse sequence to the first and second ions.
- 9. A non-transitory computer-readable medium including computer program instructions, which when executed by an information processing system, cause the information processing system to:
select a gate duration value and a detuning value of a pulse sequence used to perform an entangling gate operation on a first ion and a second ion in a chain of trapped ions, each of the trapped ions having two frequency-separated states, wherein the pulse sequence comprises a plurality of pulse segments; measure frequencies of collective motional modes of the chain of trapped ions in a direction perpendicular to a direction that the chain of trapped ions are aligned; compute a value of an entangling interaction between the first and second ions and compute values of phase space trajectories of the collective motional modes for the first and second ions, based on the selected gate duration value, the selected detuning value, and the measured frequencies of the collective motional modes; determine an intensity of each of the plurality of pulse segments based on the computed values of the entanglement interaction and the computed values of the phase space trajectories; generate the pulse sequence by connecting the plurality of pulse segments, each of the plurality of pulse segments having the determined intensity and a pulse shape with ramps formed using a spline at an start and an end of each of the plurality of pulse segments; and apply the generated pulse sequence to the first and second ions.
- 17. A quantum computing system, comprising:
a chain of trapped ions, each of the trapped ions having two hyperfine states defining a qubit and an excited state; one or more lasers configured to emit a laser beam that is split into a pair of non-copropagating laser beams having a first frequency and a second frequency that is provided to a first ion and a second ion in the chain of trapped ions, wherein the pair of non-copropagating laser beams are configured to cause Rabi flopping of the first ion and the second ion between each of the two hyperfine states and the excited state, and a controller configured to:
select a gate duration value and a detuning value of a pulse sequence used to perform an entangling gate operation on a first ion and a second ion in a chain of trapped ions, each of the trapped ions having two frequency-separated states defining a qubit, wherein the pulse sequence comprises a plurality of pulse segments;
measure frequencies of collective motional modes of the chain of trapped ions in a direction perpendicular to a direction that the chain of trapped ions are aligned;
compute a value of an entangling interaction between the first and second ions and compute values of phase space trajectories of the collective motional modes for the first and second ions based on the selected gate duration value, the selected detuning value, and the measured frequencies of the collective motional modes;
determine an intensity of each of the plurality of pulse segments based on the computed values of the entanglement interaction and the computed values of the phase space trajectories;
generate the pulse sequence by connecting the plurality of pulse segments, each of the plurality of pulse segments having the determined intensity and a pulse shape with ramps formed using a spline at a start and an end of each of the plurality of pulse segments; and
apply the generated pulse sequence to the first and second ions.
