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.

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.

In methods for simulating the evolution of a real-world quantum system over time, a state-preparation sequence of quantum gates is applied to a qubit register of a quantum computer. The state-preparation sequence is configured to prepare in the qubit register an initial model state representing an initial state of the real-world quantum system. A Hamiltonian operator for the real-world quantum system is received and used in the example method. The Hamiltonian operator represents two-body potential-energy interactions in a factorized form comprising at least one Majorana operator. A time-evolution-operator sequence of quantum gates comprising a block-encoded form of the Hamiltonian operator is now applied to the qubit register of the quantum computer, yielding a changed model state that represents a time-evolved state of the real-world quantum system. A measurement operation is applied subsequently to the qubit register. The measurement operation is configured to reveal an observable property of the changed model state.

In methods for simulating the evolution of a real-world quantum system over time, a state-preparation sequence of quantum gates is applied to a qubit register of a quantum computer. The state-preparation sequence is configured to prepare in the qubit register an initial model state representing an initial state of the real-world quantum system. A Hamiltonian operator for the real-world quantum system is received and used in the example method. The Hamiltonian operator represents two-body potential-energy interactions in a factorized form comprising at least one Majorana operator. A time-evolution-operator sequence of quantum gates comprising a block-encoded form of the Hamiltonian operator is now applied to the qubit register of the quantum computer, yielding a changed model state that represents a time-evolved state of the real-world quantum system. A measurement operation is applied subsequently to the qubit register. The measurement operation is configured to reveal an observable property of the changed model state.

Systems and methods that address an optimized method to handle portfolio constraints such as integer budget constraints and solve portfolio optimization problems that map both to mixed binary and quadratic binary optimization problems. A digital processor is used to create a hierarchical clustering; this clustering is leveraged to allocate capital to sub-clusters of the hierarchy. Once the sub-clusters are sufficiently small, a quantum processor is used to solve the portfolio optimization problem. Thus, the innovation employs clustering to reduce an optimization problem to sub-problems that are sufficiently small enough to be solved using a quantum computer given available qubits.

Systems and methods that address an optimized method to handle portfolio constraints such as integer budget constraints and solve portfolio optimization problems that map both to mixed binary and quadratic binary optimization problems. A digital processor is used to create a hierarchical clustering; this clustering is leveraged to allocate capital to sub-clusters of the hierarchy. Once the sub-clusters are sufficiently small, a quantum processor is used to solve the portfolio optimization problem. Thus, the innovation employs clustering to reduce an optimization problem to sub-problems that are sufficiently small enough to be solved using a quantum computer given available qubits.

Computational systems implement problem solving using hybrid digital/quantum computing approaches. A problem may be represented as a problem graph which is larger and/or has higher connectivity than a working and/or hardware graph of a quantum processor. A quantum processor may be used determine approximate solutions, which solutions are provided as initial states to one or more digital processors which may implement classical post-processing to generate improved solutions. Techniques for solving problems on extended, more-connected, and/or “virtual full yield” variations of the processor's actual working and/or hardware graphs are provided. A method of operation in a computational system comprising a quantum processor includes partitioning a problem graph into sub-problem graphs, and embedding a sub-problem graph onto the working graph of the quantum processor. The quantum processor and a non-quantum processor-based device generate partial samples. A controller causes a processing operation on the partial samples to generate complete samples.

Computational systems implement problem solving using hybrid digital/quantum computing approaches. A problem may be represented as a problem graph which is larger and/or has higher connectivity than a working and/or hardware graph of a quantum processor. A quantum processor may be used determine approximate solutions, which solutions are provided as initial states to one or more digital processors which may implement classical post-processing to generate improved solutions. Techniques for solving problems on extended, more-connected, and/or “virtual full yield” variations of the processor's actual working and/or hardware graphs are provided. A method of operation in a computational system comprising a quantum processor includes partitioning a problem graph into sub-problem graphs, and embedding a sub-problem graph onto the working graph of the quantum processor. The quantum processor and a non-quantum processor-based device generate partial samples. A controller causes a processing operation on the partial samples to generate complete samples.

A quantum-attack resistant operating system for use in a key management mechanism which is a full solution of cyber-security for quantum transmission via optical paths, in order to detect and bypass quantum computing attacks, or to perform quantum counterattacks, during various procedures of quantum key managements; wherein the system avoids the attacks of key tampering, destroying, detecting, and blocking, from other quantum systems in a quantum key storage phase; meanwhile, it also avoids the sniffing from other quantum systems on key entangled properties, in a quantum key clearing phase; in addition, in a quantum key recycling phase, facing quantum computing attacks, it not only can disrupt the judgement of other systems on key verification, but also consumes the computing resources on the attacker side; thereby the present invention provides a protection mechanism which cannot be achieved by a conventional PQC (Post-quantum cryptography) solution.

A quantum-attack resistant operating system for use in a key management mechanism which is a full solution of cyber-security for quantum transmission via optical paths, in order to detect and bypass quantum computing attacks, or to perform quantum counterattacks, during various procedures of quantum key managements; wherein the system avoids the attacks of key tampering, destroying, detecting, and blocking, from other quantum systems in a quantum key storage phase; meanwhile, it also avoids the sniffing from other quantum systems on key entangled properties, in a quantum key clearing phase; in addition, in a quantum key recycling phase, facing quantum computing attacks, it not only can disrupt the judgement of other systems on key verification, but also consumes the computing resources on the attacker side; thereby the present invention provides a protection mechanism which cannot be achieved by a conventional PQC (Post-quantum cryptography) solution.