dorsal/arxiv
View SchemaInferring superposition and entanglement from measurements in a single basis
| Authors | Bella Schelpe, Adrian Kent, William Munro, Tim Spiller |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0208060 |
| URL | https://arxiv.org/abs/quant-ph/0208060 |
| DOI | 10.1103/PhysRevA.67.052316 |
| Journal | Phys. Rev. A 67, 052316 (2003) |
Abstract
We discuss what can be inferred from measurements on one- and two-qubit systems using a single measurement basis at various times. We show that, given reasonable physical assumptions, carrying out such measurements at quarter-period intervals is enough to demonstrate coherent oscillations of one or two qubits between the relevant measurement basis states. One can thus infer from such measurements alone that an approximately equal superposition of two measurement basis states has been created in a coherent oscillation experiment. Similarly, one can infer that a near maximally entangled state of two qubits has been created in an experiment involving a putative SWAP gate. These results apply even if the relevant quantum systems are only approximate qubits. We discuss applications to fundamental quantum physics experiments and quantum information processing investigations.
{
"annotation_id": "3c2b9eac-d29d-4c47-95d0-21e87182118a",
"date_created": "2026-03-02T18:01:52.863000Z",
"date_modified": "2026-03-02T18:01:52.863000Z",
"file_hash": "59a8dfc9f25171ffe02ac46ecd403fd5129d2bb8fd077d1f0e8694e74e96719f",
"private": false,
"record": {
"abstract": "We discuss what can be inferred from measurements on one- and two-qubit\nsystems using a single measurement basis at various times. We show that, given\nreasonable physical assumptions, carrying out such measurements at\nquarter-period intervals is enough to demonstrate coherent oscillations of one\nor two qubits between the relevant measurement basis states. One can thus infer\nfrom such measurements alone that an approximately equal superposition of two\nmeasurement basis states has been created in a coherent oscillation experiment.\nSimilarly, one can infer that a near maximally entangled state of two qubits\nhas been created in an experiment involving a putative SWAP gate. These results\napply even if the relevant quantum systems are only approximate qubits. We\ndiscuss applications to fundamental quantum physics experiments and quantum\ninformation processing investigations.",
"arxiv_id": "quant-ph/0208060",
"authors": [
"Bella Schelpe",
"Adrian Kent",
"William Munro",
"Tim Spiller"
],
"categories": [
"quant-ph",
"cond-mat.supr-con"
],
"doi": "10.1103/PhysRevA.67.052316",
"journal_ref": "Phys. Rev. A 67, 052316 (2003)",
"title": "Inferring superposition and entanglement from measurements in a single basis",
"url": "https://arxiv.org/abs/quant-ph/0208060"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "9302dc6d-16c3-4b34-9d1e-a0f91e36390d",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}