The present invention provides devices, systems, and methods for producing bi-photons without the need for complex alignment or source design by the user. The invention provides a tunable source of high-brightness, high-visibility, bi-photons that can be configured for a number of applications.

A channel between quantum controller modules (e.g., pulse processors) is operable to communicate high speed data required for processing qubit states that may be distributed across a quantum computer. The latency of the communication channel is deterministic and controllable according to a system clock domain.

A channel between quantum controller modules (e.g., pulse processors) is operable to communicate high speed data required for processing qubit states that may be distributed across a quantum computer. The latency of the communication channel is deterministic and controllable according to a system clock domain.

A method of, and module for, converting position or momentum correlation of correlated photon pairs to a polarization entangled photon pair, and a source for polarization entangled photon pairs. The method comprises a conversion step of separating the correlated photon pairs into first and second groups based on their generated position at the crystal (position correlation) or their direction about the propagation axis (momentum correlation) and rotating a polarization of the first correlated photon pair group such that the polarization of the first correlated pair group is at 90 degrees relative to the polarization of the second correlated photon pair group; and a combining step of combining the first and second correlated photon pairs such that at least respective portions of respective spatial distributions of the first and second photon pair groups overlap with negligible wavelength dependent phase difference.

A method of, and module for, converting position or momentum correlation of correlated photon pairs to a polarization entangled photon pair, and a source for polarization entangled photon pairs. The method comprises a conversion step of separating the correlated photon pairs into first and second groups based on their generated position at the crystal (position correlation) or their direction about the propagation axis (momentum correlation) and rotating a polarization of the first correlated photon pair group such that the polarization of the first correlated pair group is at 90 degrees relative to the polarization of the second correlated photon pair group; and a combining step of combining the first and second correlated photon pairs such that at least respective portions of respective spatial distributions of the first and second photon pair groups overlap with negligible wavelength dependent phase difference.

Methods, systems and apparatus for performing windowed quantum arithmetic. In one aspect, a method for performing a product addition operation includes: determining multiple entries of a lookup table, comprising, for each index in a first set of indices, multiplying the index value by a scalar for the product addition operation; for each index in a second set of indices, determining multiple address values, comprising extracting source register values corresponding to indices between i) the index in the second set of indices, and ii) the index in the second set of indices plus the predetermined window size; and adjusting values of a target quantum register based on the determined multiple entries of the lookup table and the determined multiple address values.

Methods, systems and apparatus for performing windowed quantum arithmetic. In one aspect, a method for performing a product addition operation includes: determining multiple entries of a lookup table, comprising, for each index in a first set of indices, multiplying the index value by a scalar for the product addition operation; for each index in a second set of indices, determining multiple address values, comprising extracting source register values corresponding to indices between i) the index in the second set of indices, and ii) the index in the second set of indices plus the predetermined window size; and adjusting values of a target quantum register based on the determined multiple entries of the lookup table and the determined multiple address values.

Techniques regarding resetting highly excited qubits 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 reset component that can de-excite a qubit system to a target state by transitioning a population of a first excited state of the qubit system to a ground state and by applying a signal to the qubit system that transitions a population of a second excited state to the first excited state.

Techniques regarding resetting highly excited qubits 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 reset component that can de-excite a qubit system to a target state by transitioning a population of a first excited state of the qubit system to a ground state and by applying a signal to the qubit system that transitions a population of a second excited state to the first excited state.

Systems and methods for operating a quantum network system. The methods comprise, by a network node: generating optical clock pulses and photons using the optical clock pulses; generating a combined signal by combining the optical clock pulses with at least some of the photons such that a consistent temporal offset exits between the optical clock pulses and the first photons and/or a wave function of each photon at least partially overlaps an envelope of a respective one of the optical clock pulses; and transmitting the combined signal over a first quantum channel in which the optical clock pulses co-propagate with the photons.