# US 2020/0401925 A1 · Quantum circuit topology selection based on frequency collisions between qubits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401925 A1 - Document ID: US20200401925A1 - Status: Published application - Kind: A1 - Application number: 16/449,976 - Filed: 2019-06-24 - Published: 2020-12-24 - Earliest claimed: 2019-06-24 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Jared Barney Hertzberg; Rasit Onur Topaloglu - Web page: https://patentgrep.com/patent/US20200401925A1 ## CPC - G06N 10/20: Models of quantum computing, e.g. quantum circuits or universal quantum computers - G06F 16/9024: {Graphs; Linked lists (G06F16/9027 takes precedence)} - G06F 30/20: Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) - G06F 30/30: Circuit design - G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Systems, computer-implemented methods, and computer program products that can facilitate quantum circuit topology selection based on frequency collisions between qubits, are described. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a simulation component that simulates operation of qubits in a subgraph topology of a graph representing a topology of a quantum circuit to determine a quantity of frequency collisions between the qubits. The computer executable components can further comprise a selection component that selects a quantum circuit topology based on the quantity of frequency collisions between the qubits. ## Claims ### Claim 1 A system, comprising: a memory that stores computer executable components; and a processor that executes the computer executable components stored in the memory, wherein the computer executable components comprise: a simulation component that simulates operation of qubits in a subgraph topology of a graph representing a topology of a quantum circuit to determine a quantity of frequency collisions between the qubits; and a selection component that selects a quantum circuit topology based on the quantity of frequency collisions between the qubits. ### Claim 2 (depends on 1) The system of claim 1, wherein the subgraph topology comprises at least one of a two graph node topology, a three graph node topology, a multiple graph node topology, a rotated version of the subgraph topology, or a defined collision generating topology. ### Claim 3 (depends on 1) The system of claim 1, wherein the computer executable components further comprise: a model component that generates the graph, and wherein the graph comprises graph nodes representing the qubits and one or more graph edges coupled to the graph nodes representing one or more qubit coupling devices coupled to the qubits. ### Claim 4 (depends on 1) The system of claim 1, wherein the computer executable components further comprise: a match component that matches the subgraph topology to a collision generating topology. ### Claim 5 (depends on 1) The system of claim 1, wherein the computer executable components further comprise: a scale component that determines a quantity of one or more instances of the subgraph topology in the graph and determines a total quantity of frequency collisions corresponding to the topology of the quantum circuit based on the quantity of the one or more instances of the subgraph topology in the graph and the quantity of frequency collisions between the qubits in the subgraph topology. ### Claim 6 (depends on 1) The system of claim 1, wherein the computer executable components further comprise: a parameter component that determines one or more parameters corresponding to at least one of the qubits, the topology of the quantum circuit, or the quantum circuit that provide a defined yield. ### Claim 7 (depends on 1) The system of claim 1, wherein the selection component selects the quantum circuit topology from a plurality of quantum circuit topologies based on at least one of a defined yield or a defined quantity of frequency collisions between at least two qubits of one or more of the plurality of quantum circuit topologies, thereby facilitating at least one of improved efficiency or performance of at least one of the simulation component or the processor. ### Claim 8 A computer-implemented method, comprising: simulating, by a system operatively coupled to a processor, operation of qubits in a subgraph topology of a graph representing a topology of a quantum circuit to determine a quantity of frequency collisions between the qubits; and selecting, by the system, a quantum circuit topology based on the quantity of frequency collisions between the qubits. ### Claim 9 (depends on 8) The computer-implemented method of claim 8, wherein the subgraph topology comprises at least one of a two graph node topology, a three graph node topology, a multiple graph node topology, a rotated version of the subgraph topology, or a defined collision generating topology. ### Claim 10 (depends on 8) The computer-implemented method of claim 8, further comprising: generating, by the system, the graph, wherein the graph comprises graph nodes representing the qubits and one or more graph edges coupled to the graph nodes representing one or more qubit coupling devices coupled to the qubits. ### Claim 11 (depends on 8) The computer-implemented method of claim 8, further comprising: matching, by the system, the subgraph topology to a collision generating topology. ### Claim 12 (depends on 8) The computer-implemented method of claim 8, further comprising: determining, by the system, a quantity of one or more instances of the subgraph topology in the graph; and determining, by the system, a total quantity of frequency collisions corresponding to the topology of the quantum circuit based on the quantity of the one or more instances of the subgraph topology in the graph and the quantity of frequency collisions between the qubits in the subgraph topology. ### Claim 13 (depends on 8) The computer-implemented method of claim 8, further comprising: determining, by the system, one or more parameters corresponding to at least one of the qubits, the topology of the quantum circuit, or the quantum circuit that provide a defined yield. ### Claim 14 (depends on 8) The computer-implemented method of claim 8, wherein the selecting comprises: selecting, by the system, the quantum circuit topology from a plurality of quantum circuit topologies based on at least one of a defined yield or a defined quantity of frequency collisions between at least two qubits of one or more of the plurality of quantum circuit topologies, thereby facilitating at least one of improved efficiency or performance of the processor. ### Claim 15 A computer program product facilitating quantum circuit topology selection based on frequency collisions between qubits, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to: simulate, by the processor, operation of qubits in a subgraph topology of a graph representing a topology of a quantum circuit to determine a quantity of frequency collisions between the qubits; and select, by the processor, a quantum circuit topology based on the quantity of frequency collisions between the qubits. ### Claim 16 (depends on 15) The computer program product of claim 15, wherein the subgraph topology comprises at least one of a two graph node topology, a three graph node topology, a multiple graph node topology, a rotated version of the subgraph topology, or a defined collision generating topology. ### Claim 17 (depends on 15) The computer program product of claim 15, wherein the program instructions are further executable by the processor to cause the processor to: generate, by the processor, the graph, and wherein the graph comprises graph nodes representing the qubits and one or more graph edges coupled to the graph nodes representing one or more qubit coupling devices coupled to the qubits. ### Claim 18 (depends on 15) The computer program product of claim 15, wherein the program instructions are further executable by the processor to cause the processor to: match, by the processor, the subgraph topology to a collision generating topology. ### Claim 19 (depends on 15) The computer program product of claim 15, wherein the program instructions are further executable by the processor to cause the processor to: determine, by the processor, a quantity of one or more instances of the subgraph topology in the graph; and determine, by the processor, a total quantity of frequency collisions corresponding to the topology of the quantum circuit based on the quantity of the one or more instances of the subgraph topology in the graph and the quantity of frequency collisions between the qubits in the subgraph topology. ### Claim 20 A system, comprising: a memory that stores computer executable components; and a processor that executes the computer executable components stored in the memory, wherein the computer executable components comprise: a simulation component that simulates operation of qubits in multiple types of subgraph topologies of a graph representing a topology of a quantum circuit to determine quantities of different types of frequency collisions between the qubits; and a selection component that selects a quantum circuit topology based on the quantities of the different types of frequency collisions between the qubits. ### Claim 21 (depends on 20) The system of claim 20, wherein the computer executable components further comprise: a match component that matches one or more of the multiple types of subgraph topologies to one or more collision generating topologies, and wherein the multiple types of subgraph topologies comprise at least one of a two graph node topology, a three graph node topology, a multiple graph node topology, a rotated version of one of the multiple types of subgraph topologies, or a defined collision generating topology. ### Claim 22 (depends on 20) The system of claim 20, wherein the computer executable components further comprise: a scale component that determines a quantity of one or more instances of the multiple types of subgraph topologies in the graph and determines a total quantity of different types of frequency collisions corresponding to the topology of the quantum circuit based on the quantity of the one or more instances of the multiple types of subgraph topologies in the graph and the quantities of the different types of frequency collisions between the qubits in the multiple types of subgraph topologies. ### Claim 23 A computer-implemented method, comprising: simulating, by a system operatively coupled to a processor, operation of qubits in multiple types of subgraph topologies of a graph representing a topology of a quantum circuit to determine quantities of different types of frequency collisions between the qubits; and selecting, by the system, a quantum circuit topology based on the quantities of the different types of frequency collisions between the qubits. ### Claim 24 (depends on 23) The computer-implemented method of claim 23, further comprising: matching, by the system, one or more of the multiple types of subgraph topologies to one or more collision generating topologies, wherein the multiple types of subgraph topologies comprise at least one of a two graph node topology, a three graph node topology, a multiple graph node topology, a rotated version of one of the multiple types of subgraph topologies, or a defined collision generating topology. ### Claim 25 (depends on 23) The computer-implemented method of claim 23, further comprising: determining, by the system, a quantity of one or more instances of the multiple types of subgraph topologies in the graph; and determining, by the system, a total quantity of different types of frequency collisions corresponding to the topology of the quantum circuit based on the quantity of the one or more instances of the multiple types of subgraph topologies in the graph and the quantities of the different types of frequency collisions between the qubits in the multiple types of subgraph topologies.