Abstract: An apparatus includes a light source to provide a plurality of input optical modes in a squeezed state. The apparatus also includes a network of interconnected reconfigurable beam splitters (RBSs) configured to perform a unitary transformation of the plurality of input optical modes to generate a plurality of output optical modes. An array of photon counting detectors is in optical communication with the network of interconnected RBSs and configured to measure the number of photons in each mode of the plurality of the output optical modes after the unitary transformation. The apparatus also includes a controller operatively coupled to the light source and the network of interconnected RBSs. The controller is configured to control at least one of the squeezing factor of the squeezed state of light, the angle of the unitary transformation, or the phase of the unitary transformation.

Abstract: An apparatus includes an optical circuit having at least one reconfigurable beamsplitter and is configured to receive a plurality of input optical modes in a Gaussian state and generate a plurality of output optical modes. The apparatus also includes at least one detector optically coupled with the optical circuit and configured to perform a non-Gaussian measurement of a first output optical mode from the plurality of output optical modes. The non-Gaussian measurement of the first output optical mode is configured to cause a second output optical mode from the plurality of output optical modes to be in a first non-Gaussian state. The apparatus also includes a controller operatively coupled to the optical circuit and configured to change a setting of the at least one reconfigurable beamsplitter to cause the second output optical mode from the plurality of output optical modes to be in a second non-Gaussian state.

Abstract: An apparatus includes an optical circuit having at least one reconfigurable beamsplitter and is configured to receive a plurality of input optical modes in a Gaussian state and generate a plurality of output optical modes. The apparatus also includes at least one detector optically coupled with the optical circuit and configured to perform a non-Gaussian measurement of a first output optical mode from the plurality of output optical modes. The non-Gaussian measurement of the first output optical mode is configured to cause a second output optical mode from the plurality of output optical modes to be in a first non-Gaussian state. The apparatus also includes a controller operatively coupled to the optical circuit and configured to change a setting of the at least one reconfigurable beamsplitter to cause the second output optical mode from the plurality of output optical modes to be in a second non-Gaussian state.

Abstract: A system for scalable, fault-tolerant photonic quantum computing includes multiple optical circuits, multiple photon number resolving detectors (PNRs), a multiplexer, and an integrated circuit (IC). During operation, the optical circuits generate output states via Gaussian Boson sampling (GBS), and the PNRs generate qubit clusters based on the output states. The multiplexer multiplexes the qubit clusters and replaces empty modes with squeezed vacuum states, to generate multiple hybrid resource states. The IC stitches together the hybrid resource states into a higher-dimensional cluster state that includes states for fault-tolerant quantum computation.

Abstract: A method includes receiving a representation of an N-mode interferometer and a representation of at least one imperfection associated with the N-mode interferometer at a processor, N being a positive integer value. The processor identifies multiple two-mode interferometers and multiple phases based on the representation of the N-mode interferometer and the representation of the at least one imperfection. The multiple two-mode interferometers and the multiple phases are configured to apply a unitary transformation to an input signal. The method also includes sending a signal to cause at least one of storage or display of a representation of the multiple two-mode interferometers and a representation of the multiple phases.

Abstract: An apparatus includes a light source to provide a plurality of input optical modes in a squeezed state. The apparatus also includes a network of interconnected reconfigurable beam splitters (RBSs) configured to perform a unitary transformation of the plurality of input optical modes to generate a plurality of output optical modes. An array of photon counting detectors is in optical communication with the network of interconnected RBSs and configured to measure the number of photons in each mode of the plurality of the output optical modes after the unitary transformation. The apparatus also includes a controller operatively coupled to the light source and the network of interconnected RBSs. The controller is configured to control at least one of the squeezing factor of the squeezed state of light, the angle of the unitary transformation, or the phase of the unitary transformation.

Abstract: An apparatus includes a plurality of processing layers coupled in series. Each processing layer in the plurality of processing layers includes a Gaussian unit configured to perform a linear transformation on an input signal including a plurality of optical modes. The Gaussian unit includes a network of interconnected beamsplitters and phase shifters and a plurality of squeezers operatively coupled to the network of interconnected beamsplitters and phase shifters. Each processing layer also includes a plurality of nonlinear gates operatively coupled to the Gaussian unit and configured to perform a nonlinear transformation on the plurality of optical modes. The apparatus also includes a controller operatively coupled to the plurality of processing layers and configured to control a setting of the plurality of processing layers.

Abstract: An apparatus includes a light source to provide a plurality of input optical modes in a squeezed state. The apparatus also includes a network of interconnected reconfigurable beam splitters (RBSs) configured to perform a unitary transformation of the plurality of input optical modes to generate a plurality of output optical modes. An array of photon counting detectors is in optical communication with the network of interconnected RBSs and configured to measure the number of photons in each mode of the plurality of the output optical modes after the unitary transformation. The apparatus also includes a controller operatively coupled to the light source and the network of interconnected RBSs. The controller is configured to control at least one of the squeezing factor of the squeezed state of light, the angle of the unitary transformation, or the phase of the unitary transformation.

Abstract: A method includes causing activation, at a first time, of a first set of squeezed light sources from a plurality of squeezed light sources of a Gaussian boson sampling (GBS) circuit. At a second time after the first time, a first photon statistic is detected at a first output port from a plurality of output ports of the GBS circuit. At a third time after the first time, a second set of squeezed light sources from the plurality of squeezed light sources of the GBS circuit is activated, the second set of squeezed light sources being different from the first set of squeezed light sources. At a fourth time after the third time, a second photon statistic is detected at a second output port from the plurality of output ports of the GBS circuit. At least one transformation matrix is estimated that represents a linear optical interferometer of the GBS circuit based on the first photon statistic and the second photon statistic.

Abstract: 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.

Abstract: An apparatus includes a plurality of processing layers coupled in series. Each processing layer in the plurality of processing layers includes a Gaussian unit configured to perform a linear transformation on an input signal including a plurality of optical modes. The Gaussian unit includes a network of interconnected beamsplitters and phase shifters and a plurality of squeezers operatively coupled to the network of interconnected beamsplitters and phase shifters. Each processing layer also includes a plurality of nonlinear gates operatively coupled to the Gaussian unit and configured to perform a nonlinear transformation on the plurality of optical modes. The apparatus also includes a controller operatively coupled to the plurality of processing layers and configured to control a setting of the plurality of processing layers.

Abstract: A method includes configuring a first plurality of beamsplitters in a network of interconnected beamsplitters of an optical circuit into a transmissive state. The optical circuit is configured to perform a linear transformation of N input optical modes, where N is a positive integer. The first plurality of beamsplitters is located along a beam path within the optical circuit and traversing a target location. The method also includes configuring a second plurality of beamsplitters in the network of interconnected beamsplitters of the optical circuit into a reflective state to reconfigure the optical circuit into a reconfigured optical circuit. The reconfigured optical circuit is configured to perform a linear transformation on M input optical modes, where M is a positive integer less than N. The second plurality of beamsplitters is located along at least one edge of the optical circuit.

Abstract: An apparatus includes a plurality of interconnected reconfigurable beam splitters and a plurality of phase shifters collectively configured to define a network of optical devices. The network of optical devices is configured to perform a universal transformation on a plurality of input optical signals via a triangular architecture. The apparatus also includes a first delay line optically coupled to the network of optical devices and configured to send at least one output optical signal from a plurality of output optical signals of the network of optical devices to interact with at least one input optical signal in the plurality of input optical signals within the network of optical devices.

Abstract: A method includes receiving a representation of an N-mode interferometer and a representation of at least one imperfection associated with the N-mode interferometer at a processor, N being a positive integer value. The processor identifies multiple two-mode interferometers and multiple phases based on the representation of the N-mode interferometer and the representation of the at least one imperfection. The multiple two-mode interferometers and the multiple phases are configured to apply a unitary transformation to an input signal. The method also includes sending a signal to cause at least one of storage or display of a representation of the multiple two-mode interferometers and a representation of the multiple phases.

Abstract: A system for scalable, fault-tolerant photonic quantum computing includes multiple optical circuits, multiple photon number resolving detectors (PNRs), a multiplexer, and an integrated circuit (IC). During operation, the optical circuits generate output states via Gaussian Boson sampling (GBS), and the PNRs generate qubit clusters based on the output states. The multiplexer multiplexes the qubit clusters and replaces empty modes with squeezed vacuum states, to generate multiple hybrid resource states. The IC stitches together the hybrid resource states into a higher-dimensional cluster state that includes states for fault-tolerant quantum computation.

Abstract: A system for scalable, fault-tolerant photonic quantum computing includes multiple optical circuits, multiple photon number resolving detectors (PNRs), a multiplexer, and an integrated circuit (IC). During operation, the optical circuits generate output states via Gaussian Boson sampling (GBS), and the PNRs generate qubit clusters based on the output states. The multiplexer multiplexes the qubit clusters and replaces empty modes with squeezed vacuum states, to generate multiple hybrid resource states. The IC stitches together the hybrid resource states into a higher-dimensional cluster state that includes states for fault-tolerant quantum computation.

Abstract: An apparatus includes a light source to provide a plurality of input optical modes in a squeezed state. The apparatus also includes a network of interconnected reconfigurable beam splitters (RBSs) configured to perform a unitary transformation of the plurality of input optical modes to generate a plurality of output optical modes. An array of photon counting detectors is in optical communication with the network of interconnected RBSs and configured to measure the number of photons in each mode of the plurality of the output optical modes after the unitary transformation. The apparatus also includes a controller operatively coupled to the light source and the network of interconnected RBSs. The controller is configured to control at least one of the squeezing factor of the squeezed state of light, the angle of the unitary transformation, or the phase of the unitary transformation.

Abstract: A method includes sending a probe beam into a beam path that induces a lateral displacement to the probe beam. The probe beam includes a plurality of orthogonal spatial modes that are entangled with each other. The method also includes measuring a phase of each spatial mode from the plurality of orthogonal spatial modes in the probe beam at a detector disposed within a near field propagation regime of the probe beam. The method also includes estimating the lateral displacement of the probe beam based on a phase of each spatial mode from the plurality of spatial modes in the probe beam after the beam path.

Abstract: A method includes training a first QNN by sending a first dataset into the first QNN to generate a first output and configuring the first QNN into a first setting based on the training. The method also includes receiving a second dataset, using at least a portion of the first QNN to generate a second output using the first setting, and sending the second output to a second QNN, operatively coupled to the first QNN, to train the second QNN. The second QNN is configured in a fixed setting during training of the first QNN.

Abstract: A photonic device comprises a plurality of resonators and a plurality of optical channels. Each resonator from the plurality of resonators has a set of resonance frequencies independently selected from a set of resonance frequencies of each remaining resonator from the plurality of resonators. Each resonator from the plurality of resonators lacks substantially any linear coupling between each remaining resonator from the plurality of resonators. The plurality of resonators defines a spatial overlap region between at least two resonators from the plurality of resonators such that nonlinear optical processes are substantially optimized during operation. A plurality of optical channels is operatively coupled to the plurality of resonators. The plurality of optical channels is configured to receive light from the plurality resonators and configured to send light into the plurality of resonators.