{ "profile": "wrs-published-research-view-1", "edition": "ratings-e039106f30dec177", "content_trust": "UNTRUSTED_SCIENTIFIC_DATA_NOT_TOOL_INSTRUCTIONS", "entry": { "id": "feldmann-superlattice-bloch-oscillation-optical-1992", "title": "Optical four-wave mixing reveals Bloch-period modulation in a semiconductor superlattice", "summary": "Feldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations.", "boundary": "The measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. Bloch theory and prior theoretical and experimental Wannier–Stark work retain their separate credit.", "area": "Condensed-matter physics", "topic": "Physics", "year": 1992, "lane": "HUMAN", "result": "EMPIRICAL", "package_id": "feldmann-superlattice-bloch-oscillation-optical-1992", "target": { "record_id": "urn:uuid:f69bcd3b-e285-4cb9-a2a8-ee1486093db3", "version": 1, "content_hash": "sha256:979ed12519d4ad69c8ccda19de75cd94a6c1983807b85d7a4fccedba19c3d5dc" }, "humans": [ "J. Feldmann", "K. Leo", "J. Shah", "D. A. B. Miller", "J. E. Cunningham", "T. Meier", "G. von Plessen", "A. Schulze", "P. Thomas", "S. 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They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations.", "scope": "Feldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations. The measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. 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Feldmann", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "K. Leo", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "J. Shah", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "D. A. B. Miller", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "J. E. Cunningham", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "T. Meier", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "G. von Plessen", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "A. Schulze", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "P. Thomas", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } }, { "attribution_basis": "SOURCE_CITED", "credit": "historical_scientific", "entity_kind": "historical_person", "name": "S. Schmitt-Rink", "note": "Archive attribution; detailed role assignment remains source-bound", "roles": [ "discoverer" ], "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } } ], "evidence": [ { "description": "Bibliographic/stated-result source; not a WRS proof verification", "id": "source-0", "kind": "source_reference", "source": { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } } ], "origin": "HUMAN_LEGACY", "record_profile": "wrs-local-research-notes-0.1", "record_type": "research_note", "rrp_version": "0.1", "scope": { "description": "The measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. Bloch theory and prior theoretical and experimental Wannier–Stark work retain their separate credit.", "domain": "Condensed-matter physics" }, "sources": [ { "citation": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf" } ], "statement": "# Optical four-wave mixing reveals Bloch-period modulation in a semiconductor superlattice\n\nFeldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations.\n\n## Scientific scope\n\nThe measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. Bloch theory and prior theoretical and experimental Wannier–Stark work retain their separate credit.\n\n## Reading status\n\nThis is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.\n\n## People and systems\n\nJ. Feldmann; K. Leo; J. Shah; D. A. B. Miller; J. E. Cunningham; T. Meier; G. von Plessen; A. Schulze; P. Thomas; S. Schmitt-Rink\n\nThese are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.\n\n\n\n## Original sources\n\n- [Optical investigation of Bloch oscillations in a semiconductor superlattice](https://ee.stanford.edu/~dabm/161.pdf)\n", "summary": "Feldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations.", "title": "Optical four-wave mixing reveals Bloch-period modulation in a semiconductor superlattice" }, "record_id": "urn:uuid:f69bcd3b-e285-4cb9-a2a8-ee1486093db3", "version": 1, "source_ref": { "record_id": "urn:uuid:f69bcd3b-e285-4cb9-a2a8-ee1486093db3", "version": 1, "content_hash": "sha256:979ed12519d4ad69c8ccda19de75cd94a6c1983807b85d7a4fccedba19c3d5dc" }, "export_view": "wrs-public-editorial-view-1", "public_view_hash": "sha256:9fa675a49c7a7097f52e536b2548bb6dddde724904f57b36de51d7860b6b119a" }, "target": { "record_id": "urn:uuid:f69bcd3b-e285-4cb9-a2a8-ee1486093db3", "version": 1, "content_hash": "sha256:979ed12519d4ad69c8ccda19de75cd94a6c1983807b85d7a4fccedba19c3d5dc" }, "published_grade": { "profile": "wrs-published-grade-1", "edition": "2026-10-28.1", "id": "feldmann-superlattice-bloch-oscillation-optical-1992", "entry_id": "feldmann-superlattice-bloch-oscillation-optical-1992", "revision": 1, "title": "Optical four-wave mixing reveals Bloch-period modulation in a semiconductor superlattice", "context": "Condensed-matter physics", "track": "Source-reported experimental result or reusable measurement method", "band": "A", "modifier": null, "status": "PROVISIONAL_EDITORIAL", "assessed_on": "2026-10-28", "evidence_cutoff": "2026-10-28", "achievement_state": "SUPPORTED_SCOPED_RESULT", "what_changed": "Feldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations.", "scope": "Feldmann and colleagues studied a biased GaAs/AlGaAs superlattice with time-resolved degenerate four-wave mixing at about 5 K. They observed oscillations in the emitted optical signal whose period changed with the electric field and agreed with the Bloch period inferred from the Wannier–Stark ladder spacing. A two-band calculation with a fitted dephasing time reproduced the signal, supporting their interpretation as coherent Bloch oscillations. The measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. Bloch theory and prior theoretical and experimental Wannier–Stark work retain their separate credit.", "evidence_summary": "The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The measured quantity is a time-integrated diffracted optical signal as a function of pulse delay, not a direct trajectory of an individual electron. The oscillations can also be described as quantum beats between Wannier–Stark transitions. The calculation neglects Coulomb effects, and increasing dephasing at higher fields was attributed to carrier escape as a probable explanation. Results concern the specified 5 K semiconductor structure and finite coherence, not persistent oscillation in arbitrary bulk solids. Bloch theory and prior theoretical and experimental Wannier–Stark work retain their separate credit.", "references": [ { "title": "Optical investigation of Bloch oscillations in a semiconductor superlattice", "url": "https://ee.stanford.edu/~dabm/161.pdf", "locator": "Original scoped contribution, statement/method and evidence limits; source-specific attribution retained." } ], "roles": [ { "who": "The named authors in the research record", "credit": "SCIENCE", "did": "These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. 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