{"id":20930182,"url":"https://github.com/dpbm/ghz","last_synced_at":"2026-04-13T12:01:26.672Z","repository":{"id":247982404,"uuid":"815292853","full_name":"Dpbm/ghz","owner":"Dpbm","description":"Testing GHZ state creation","archived":false,"fork":false,"pushed_at":"2024-07-27T15:33:57.000Z","size":8343,"stargazers_count":0,"open_issues_count":1,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-12-27T22:44:21.003Z","etag":null,"topics":["circuit-cutting","circuit-knitting","error-mitigation","ghz-state","ibm-quantum","python","qiskit","qiskit-sampler","quantum-computing","quantum-states"],"latest_commit_sha":null,"homepage":"https://dpbm.github.io/ghz/","language":"Jupyter Notebook","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/Dpbm.png","metadata":{"files":{"readme":"readme.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2024-06-14T19:33:16.000Z","updated_at":"2024-07-27T15:33:41.000Z","dependencies_parsed_at":"2024-07-11T18:16:14.483Z","dependency_job_id":"50e7baae-5166-448a-befe-b0d745b9ead3","html_url":"https://github.com/Dpbm/ghz","commit_stats":null,"previous_names":["dpbm/ghz"],"tags_count":1,"template":false,"template_full_name":null,"purl":"pkg:github/Dpbm/ghz","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Dpbm%2Fghz","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Dpbm%2Fghz/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Dpbm%2Fghz/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Dpbm%2Fghz/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/Dpbm","download_url":"https://codeload.github.com/Dpbm/ghz/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/Dpbm%2Fghz/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":31751705,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-04-13T09:16:15.125Z","status":"ssl_error","status_checked_at":"2026-04-13T09:16:05.023Z","response_time":93,"last_error":"SSL_connect returned=1 errno=0 peeraddr=140.82.121.6:443 state=error: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["circuit-cutting","circuit-knitting","error-mitigation","ghz-state","ibm-quantum","python","qiskit","qiskit-sampler","quantum-computing","quantum-states"],"created_at":"2024-11-18T21:29:42.613Z","updated_at":"2026-04-13T12:01:26.644Z","avatar_url":"https://github.com/Dpbm.png","language":"Jupyter Notebook","funding_links":[],"categories":[],"sub_categories":[],"readme":"# GHZ\n\nThis repo contains some tests on creating `GHZ` states using [Qiskit](https://www.ibm.com/quantum/qiskit).\n\nFor this project, the idea was to explore some different techniques to create big `GHZ states`.\n\nThe techniques I used were:\n\n- circuit knitting\n- topology mapping\n- circuit transpilation (using Qiskit `PassManager` and `Sampler`)\n\nIn total, 4 circuits were built mixing some of these techniques.\n\n## Circuits\n\n### 5 qubits GHZ - [notebook](./circuit-cutting-test.ipynb)\n\n![GHZ 5 qubits circuit](./5-qubits-GHZ-circuit.png)\n\nThis one was the first test done with circuit knitting, using the `cutqc` module from `circuit knitting toolbox` package.\n\nHere the circuit was cut in 2 separated parts, measured and them joined together.\n\n![GHZ 5 qubits dists](./5-qubits-GHZ-circuit-cutting-test.png)\n\n| cuts                                          |  exported data                                                        |\n|-----------------------------------------------|-----------------------------------------------------------------------|\n|[subcircuit 0](./5-qubits-GHZ-subcircuit-0.qpy)|[cuts](./5-qubits-GHZ-cuts.json)                                       |\n|[subcircuit 1](./5-qubits-GHZ-subcircuit-1.qpy)|[probabilities](./5-qubits-GHZ-probs.json)                             |\n|                                               |[reconstructed probabilities](./5-qubits-GHZ-reconstructed-probs.json) |\n\n\n### 16 qubits GHZ - [notebook](./16-qubits-ghz-circuit-knitting.ipynb)\n\n![GHZ 16 qubits circuit](./16-qubits-GHZ-circuit.png)\n\nThe second is a 16 qubits circuit, following the topology of IBM's Guadalupe backend. After mapping each qubit connection, the resulting distribution after simulating was:\n\n![GHZ 16 qubits IBM Guadalupe simulation](./16-qubits-GHZ-counts.png)\n\nThis one, was also cut using `cutqc` giving the following results:\n\n![GHZ 16 qubits cut result](./16-qubits-GHZ-circuit-cutting.png)\n\n| cuts                                           |  exported data                                                        |\n|------------------------------------------------|-----------------------------------------------------------------------|\n|[subcircuit 0](./16-qubits-GHZ-subcircuit-0.qpy)|[cuts](./16-qubits-GHZ-cuts.json)                                      |\n|[subcircuit 1](./16-qubits-GHZ-subcircuit-1.qpy)|[probabilities](./16-qubits-GHZ-probs.json)                            |\n|[subcircuit 2](./16-qubits-GHZ-subcircuit-2.qpy)|[reconstructed probabilities](./16-qubits-GHZ-reconstructed-probs.json)|\n\n## 28 qubits GHZ - [notebook](./28-qubits-ghz-circuit-knitting.ipynb)\n\n![GHZ 28 qubits circuit](./28-qubits-GHZ-circuit.png)\n\nThe 28 qubits version was based on IBM's Cambridge backend, however this one wasn't executed due to hardware issues.\nNevertheless, some cuts were done.\n\n| cuts                                           |  exported data                                                        |\n|------------------------------------------------|-----------------------------------------------------------------------|\n|[subcircuit 0](./28-qubits-GHZ-subcircuit-0.qpy)|[cuts](./28-qubits-GHZ-cuts.json)                                      |\n|[subcircuit 1](./28-qubits-GHZ-subcircuit-1.qpy)|[probabilities](./28-qubits-GHZ-probs.json)                            |\n|[subcircuit 2](./28-qubits-GHZ-subcircuit-2.qpy)|                                                                       |\n|[subcircuit 3](./28-qubits-GHZ-subcircuit-3.qpy)|                                                                       |\n\n## 127 qubits GHZ - [notebook](./ghz-127-qubits.ipynb)\n\n![GHZ 127 qubits circuit](./127-qubits-GHZ-circuit.png)\n\nThe biggest one, is based on IBM's Osaka backend. This one, was transpiled and executed on real hardware, the outcomes were the following:\n\n![osaka results](./127-qubits-GHZ-counts.png)\n\nThese results seem really wrong, once the expected was nearly 50% of probability for $|00000...0\\rangle$ and 50% for $|11111...1\\rangle$. However, due the amount of errors for `cx` gates, it's probably the accurate result for a real device.\n\nThis effect can be seem in a local test executed with 20 qubits.\n\n![osaka 20 qubits](./test-osaka-ghz-state-20-qubit.png)\n\n![osaka 20 qubits counts](./20-qubits-ghz-counts-local-job.png)\n\nEven that the extreme states are with high probability, it tends to deviate at each qubit addition.","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdpbm%2Fghz","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdpbm%2Fghz","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdpbm%2Fghz/lists"}